Fundamentals of Computers Unit II

Computer Fundamental

Unit II

Use of MS-Office:

Microsoft Office or Microsoft Office System is a collection of computer programs made by Microsoft. The programs are created for all users. There are different versions of the software for home users and for business users

Main Programs:

Microsoft Word

Microsoft Word is a word processor that lets users type text into the document and add images, clip art, diagrams and different font or design choices. The main file formats are .doc and .docx. it also helps to check the spelling and find the meaning of words.

Microsoft Excel

Microsoft Excel is a spreadsheet and mathematics program that can make calculations and graphs based on data the user enters. The main file formats are .xls and .xlsx. Most computers at schools do not have Microsoft Office 2007/2010, so the file format .xlsx (which is the 2007/2010 format) will not work. Try to save it as a .xls file whenever possible.

Microsoft PowerPoint

Microsoft PowerPoint is a program that creates presentations and slideshows. They can have text, drawing, pictures and media. They can also be set up to show on a projector.

Microsoft Outlook

Microsoft Outlook is an email client that can send and receive emails. The user can add a contact list, multiple calendars.

Microsoft Access

Microsoft Access is a database program where people can store data over many tables.

What is Microsoft Access made up of?

The Microsoft® Access Database is made up of 7 major components:

Tables; Relationships; Queries; Forms; Reports; Macros; Modules.

The following gives a quick overview of each component.

TablesThe tables are the backbone and the storage container of the data entered into the database. If the tables are not set up correctly, with the correct relationships, then the database may be slow, give you the wrong results or not react the way you expect. So, take a bit of time when setting up your tables. Queries, forms, etc. are usually based on a table.

The tables that contain data look a bit like a table in Microsoft® Word or a Microsoft® Excel Spreadsheet, when opened. They have columns and rows as does a table in Microsoft® Word and an Excel worksheet. Each of the columns will have a field name at the top and each of the rows will represent a record.

As an example: 

Relationships

Relationships are the bonds you build between the tables. They join tables that have associated elements. To do this there is a field in each table, which is linked to each other, and have the same values.

Queries

Are the means of manipulating the data to display in a form or a report. Queries can sort, calculate, group, filter, join tables, update data, delete data, etc. Their power is immense. The Microsoft® Access database query language is SQL (Structured Query Language). The need to know SQL is not required in the early stages of learning Access. Microsoft® Access writes the SQL for you, after you tell it what you want, in the Design view of the queries window.

Forms

Forms are the primary interface through which the users of the database enter data. The person who enters the data will interact with forms regularly. The programmer can set the forms to show only the data required. By using queries, properties, macros and VBA (Visual Basic for Applications), the ability to add, edit and delete data can also be set. Forms can be set up and developed to reflect the use they will be required for.

Reports

Reports are the results of the manipulation of the data you have entered into the database. Unlike forms, they cannot be edited. Reports are intended to be used to output data to another device or application, i.e. printer, fax, Microsoft® Word or Microsoft® Excel.

Macros

Macros are an automatic way for Access to carry out a series of actions for the database. Access gives you a selection of actions that are carried out in the order you enter. Macros can open forms; run queries, change values of a field, run other Macros, etc. the list is almost endless.

Modules

Modules are the basis of the programming language that supports Microsoft® Access, The module window is where you can write and store Visual Basic for Applications (VBA).

Microsoft Publisher

Microsoft Publisher is a program that lets people make layouts for newsletters and presentations to print.

Computer Networks

A collection of computing devices connected in order to communicate and share resources Connections between computing devices can be physical using wires or cables or wireless using radio waves or infrared signals.

Node (host)

Any device on a network

Data transfer rate (bandwidth)

The speed with which data is moved from one place to another on a network

Computer networks have opened up an entire frontier in the world of computing called the client/server model

Protocol

A set of rules that defines how data is formatted and processed on a network; i.e., rules that allow client/server interaction

File server

A computer that stores and manages files for multiple users on a network

Web server

A computer dedicated to responding to requests (from the browser client) for web pages

Types of Networks

Local-area network (LAN)

A network that connects a relatively small number of machines in a relatively close geographical area

Ring topology connects all nodes in a closed loop on which messages travel in one direction

Star topology centers around one node to which all others are connected and through which all messages are sent

Bus topology nodes are connected to a single communication line that carries messages in both directions

Wide-area network (WAN)

A network that connects local-area networks over a potentially large geographic distance

Metropolitan-area network (MAN)

The communication infrastructures that have been developed in and around large cities

Gateway

One particular set up to handle all communication going between that LAN and other networks

Internet

A wide area network that spans the planet

Internet Connections

Internet backbone

A set of high-speed networks that carry Internet traffic, provided by companies such as AT&T, Verizon, GTE, British Telecom, and IBM

Internet service provider (ISP)

A company that provides other companies or individuals with access to the Internet.

Various technologies available to connect a home computer to the Internet

Phone modem converts computer data into an analog audio signal for transfer over a telephone line, and then a modem at the destination converts it back again into data

Digital subscriber line (DSL) uses regular copper phone lines to transfer digital data to and from the phone company’s central office

Cable modem uses the same line that your cable TV signals come in on to transfer the data back and forth

Broadband

A connection in which transfer speeds are faster than 768 kilobits per second

– DSL connections and cable modems are broadband connections

– The speed for downloads (getting data from the Internet to your home computer) may not be the same as uploads (sending data from your home computer to the Internet)

Packet Switching

Packet

A unit of data sent across a network

Router

A network device that directs a packet between networks toward its final destination

Packet switching

Messages are divided into fixed-sized, numbered packets; packets are individually routed to their destination, then reassembled

Open Systems

A logical progression...

Proprietary system

A system that uses technologies kept private by a particular commercial vendor

Interoperability

The ability of software and hardware on multiple machines and from multiple commercial vendors to communicate

Open systems

Systems based on a common model of network architecture and a suite of protocols used in its implementation

Network Protocols

• Network protocols are layered such that each one relies on the protocols that underlie it

• Sometimes referred to as a protocol stack

TCP/IP

Transmission Control Protocol (TCP)

Software that breaks messages into packets, hands them off to the IP software for delivery, and then orders and reassembles the packets at their destination

Internet Protocol (IP)

Software that deals with the routing of packets through the maze of interconnected networks to their final destination

User Datagram Protocol (UDP)

An alternative to TCP that is faster but less reliable

Ping

A program used to test whether a particular network computer is active and reachable

Traceroute

A program that shows the route a packet takes across the Internet

High-Level Protocols

Other protocols build on TCP/IP protocol suite

Simple Mail Transfer Protocol (SMTP) used to specify transfer of electronic mail

File Transfer Protocol (FTP) allows a user to transfer files to and from another computer

Telnet used to log onto one computer from another

Hyper Text Transfer Protocol (http) allows exchange of Web documents

Firewalls

Firewall

A gateway machine and its software that protects a network by filtering the traffic it allows

Access control policy

A set of rules established by an organization that specifies what types of network communication are permitted and denied

Network Addresses

Hostname

A name made up of words separated by dots that uniquely identifies a computer on the Internet

IP address

An address made up of four one-byte numeric values separated by dots that uniquely identifies a computer on the Internet

Domain Name System

Host number

The part of the IP address that specifies a particular host (machine) on the network Yes, but what is it?

Domain name

The part of a hostname that specifies a specific organization or group

Top-level domain (TLD)

The last section of a domain name that specifies the type of organization or its country of origin

Basic Services of the Internet

WWW:

Stands for "World Wide Web." It is important to know that this is not a synonym for the Internet. The World Wide Web, or just "the Web," as ordinary people call it, is a subset of the Internet. The Web consists of pages that can be accessed using a Web browser. The Internet is the actual network of networks where all the information resides. Things like Telnet, FTP, Internet gaming, Internet Relay Chat (IRC), and e-mail are all part of the Internet, but are not part of the World Wide Web. The Hyper-Text Transfer Protocol (HTTP) is the method used to transfer Web pages to your computer. With hypertext, a word or phrase can contain a link to another Web site. All Web pages are written in the hyper-text markup language (HTML), which works in conjunction with HTTP.

FTP:

The File Transfer Protocol (FTP) is a standard network protocol used to transfer computer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and uses separate control and data connections between the client and the server.

Telnet:

Telnet is a user command and an underlying TCP/IP protocol for accessing remote computers. Through Telnet, an administrator or another user can access someone else's computer remotely. On the Web, HTTP and FTP protocols allow you to request specific files from remote computers, but not to actually be logged on as a user of that computer. With Telnet, you log on as a regular user with whatever privileges you may have been granted to the specific application and data on that computer.

Gopher

The Gopher protocol is a TCP/IP application layer protocol designed for distributing, searching, and retrieving documents over the Internet. The Gopher protocol was strongly oriented towards a menu-document design and presented an alternative to the World Wide Web in its early stages, but ultimately HTTP became the dominant protocol. The Gopher ecosystem is often regarded as the effective predecessor of the World Wide Web.

IP addresses

An IP address is an identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination.

ISPs:

'Internet Service Provider - ISP' A company that provides access to the Internet to subscriber-based customers. An Internet Service Provider offers dial-up, cable, DSL (digital subscriber line), fiber optic or other types of Internet access.

URL

URL stands for Uniform Resource Locator. A URL is a formatted text string used by Web browsers, email clients and other software to identify a network resource on the Internet. Network resources are files that can be plain Web pages, other text documents, graphics, or programs.

Web Browser

A web browser (commonly referred to as a browser) is a software application for retrieving, presenting and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI/URL) and may be a web page, image, video or other piece of content.

Search engines

Search engines a program that searches for and identifies items in a database that correspond to keywords or characters specified by the user, used especially for finding particular sites on the World Wide Web.

Searching

Exploration of the World Wide Web by following one interesting link to another, usually with a definite objective and a planned search strategy. In comparison surfing is exploration

definite in objective but not in strategy, and browsing is exploration without a definite objective or search strategy.

Uploading & Downloading

Uploading means data is being sent from your computer to the Internet.

Examples of uploading include sending email, posting photos on a social media site and using your webcam. Even clicking on a link on a web page sends a tiny data upload.

Downloading means your computer is receiving data from the Internet.

Examples of downloading include opening a web page, receiving email, purchasing music files and watching online videos.

Applications of Information Technology

Every day, people use computers in new ways. Computers and other electronic devices are becoming increasingly affordable. They continue to be more powerful as information-processing tools as well as easier to use. Humans are continually becoming dependant on IT-enabled devices for carrying out simple tasks like remembering a phone number to complex ones like flying a fighter plane. Information Technology has applications in almost all aspects of our life. Some of the important ones are:

Science and Engineering: Scientific progress in fields like biotechnology is almost entirely dependent on the use of computers and other microprocessor-controlled devices. Using supercomputers, meteorologists predict future weather by using a combination of observations of weather conditions from many sources, a mathematical representation of the behavior of the atmosphere, and geographic data. Computer-aided design (CAD) and computer-aided manufacturing (CAM) programs have led to improved products in many fields, especially where designs tend to be very detailed. Computer programs make it possible for engineers to analyze designs of complex structures such as power plants and space stations.

Business & Commerce: One of the first and largest applications of computers is keeping and managing business and financial records. Most large companies keep the employment records of all their workers in large databases that are managed by computer programs. Similar programs and databases are used in business functions like billing customers; tracking payments received and payments to be made; and tracking supplies needed and items produced, stored, shipped, and sold. In fact, practically all the information companies need to do business involves the use of computers and Information Technology. Almost all the financial transactions in the world are done electronically. Newer technologies like m-commerce have enabled almost everybody to carry out routine financial transactions on the move.

On a smaller scale, many businesses have replaced cash registers with point-of-sale (POS) terminals. These POS terminals not only print a sales receipt for the customer but also send information to a computer database when each item is sold to maintain an inventory of items on hand and items to be ordered. Computers have also become very important in modern factories. Computer-controlled robots now do tasks that are hot, heavy, or hazardous. Robots are also used to do routine, repetitive tasks in which boredom or fatigue can lead to poor quality work.

With today's sophisticated hardware, software, and communications technologies, it is often difficult to classify a system as belonging uniquely to one specific application program. Organizations increasingly are consolidating their information needs into a single, integrated information system. Management Information System (MIS), with the Chief Information Officer (CIO) at its head, is a whole, new branch of enterprise management.

Education: The advent of Information Technology has changed the meaning of the term “literate”, with computer literacy being almost as important as basic literacy in many cases. Computer education is an essential course at the primary level in most schools across the world. With more information getting digitized every day, and the internet making it accessible to anyone across the world, students are increasingly relying on electronic sources of information rather than physical libraries for their needs. Instructional methodology has also undergone a sea change with use of images, animations, videos, presentations and e-learning to complement traditional techniques.

Governance: The concept of e-governance is one of the most novel applications of Information Technology whereby it is changing the lives of millions across the globe. Computerization of Government activities makes it easier to supervise and audit, and makes the administration more responsive to the needs of society. It also bridges the divide between the Government and the people. Technologies like touch-screen kiosks help disseminate information on land records, photo identity cards, pending bills etc. and enable even illiterate people to take more informed decisions. India is leading the world in the effective use of IT for elections.

Medicine: Information Technology plays an important role in medicine. For example, a scanner takes a series of pictures of the body by means of computerized axial tomography (CAT) or magnetic resonance imaging (MRI). A computer then combines the pictures to produce detailed three-dimensional images of the body's organs. In addition, the MRI produces images that show changes in body chemistry and blood flow. Most critical life support equipment are programmed to respond to changes in the patient’s status in split-seconds, thereby reducing the response time and risk of human error. Newer concepts like robotic surgery enable specialists to perform surgeries from remote locations. Genomic studies greatly depend on supercomputing power to develop technologies for the future.

Entertainment: IT has changed the lifestyle of most people. The convergence of various technologies has created various options for entertainment like games, streaming music and video, digital television broadcasts, satellite radio, animated movies etc. which can be accessed with the help of mobile phones, PDAs, notebook computers or on television either

with a cable connection or wirelessly using newer-generation WiFi, CDMA or GPRS technologies.