BY WELLINGTON OBOHGSS JABI

2014

COMPUTER EDUCATION

CONCEPT OF COMPUTER FILES

Specific Objectives

• Learners should be able to define computer file• Learners should be able to define record• Learners should be able to define computer files

and record• Learners should be able to define field and data

item• Learners should be able to explains types of data

items• Learners should be able to explains the file structure

Definition of computer files

•What are computer

files?

Definition of computer files

Computer files are the most basic unit of data that users can store on a disk.

Definition of computer files

Computer files are the most basic unit of data that users can store on a disk.

Every program, image, video, song and document is stored as a file.

Definition of Record

•What is a record?

Definition of Record

A record is a collection of related data items or fields.

Definition of Record

A record is a collection of related data items or fields.

Each record normally corresponds to a specific unit of information. Examples are: Employee’s name, basic salary and house rent allowance.

Definition of Field

A field is a space allocated for a particular item of information.

Field A field is a space allocated for a particular item of information.

A tax form for example contains a number of fields; one for your name, one for your tax identification number (TIN), one for your income and so on.

In a database, fields are the smallest units of information you can access. In spreadsheet fields are called cells. Data items are physically arranged as fields in a computer file. Their length may be fixed or variable. Since all individuals have 3 digit employee numbers, a 3-digit field is required to store the

particular data. Hence it is a fixed field. In contrast, since customers name vary considerably from one customer to another, a variable amount of space must be available to

store this element. This can be called variable field.In video terminology, a field is one of many still images that make up a moving picture. A field is similar to a frame but is displayed

twice as fast.

Field A field is a space allocated for a particular item of information. A tax form for example contains a number of fields; one for your name, one for your tax identification number (TIN), one for your income and so on.

In a database, fields are the smallest units of information you can access. In spreadsheet fields are called cells.

Data items are physically arranged as fields in a computer file. Their length may be fixed or variable. Since all individuals have 3 digit employee numbers, a 3-digit field is required to store the particular data. Hence it is a fixed field. In contrast, since customers name vary considerably from one customer to another, a variable amount of space must be available to store this element. This can be called variable field.In video terminology, a field is one of many still images that make up a moving picture. A field is similar to a frame but is displayed twice as fast.

Field

Data items are physically arranged as fields in a computer file.

Field

Data items are physically arranged as fields in a computer file.

Their length may be fixed or variable. Since all individuals have 3 digit employee numbers, a 3-digit field is required to store the particular data. Hence it is a fixed field.

In contrast, since customers name vary considerably from one customer to another, a variable amount of space must be available to store this element. This can be called variable field.

In video terminology, a field is one of many still images that make up a moving picture. A field is similar to a frame but is displayed twice as fast.

Data

Data item is the smallest unit of information stored in a computer file. It is a single element used to represent a fact such as an employee’s name, item price.

Types of Data items

1. Numbers2.Alphabet

3.Alphanumeric

Types of Data items

• Numeric data consist of numbers from 0 – 9• Alphabetic data consist of letters A –Z• Alphanumeric data is a combination of numbers

and letters, can also refer to collection of Latin letters and Arabic digits or text constructed from these collection. There are either 36 (Single case) or 62 (Case Sensitive) alphanumeric characters. The alphanumeric data set consist of number 0-9 and letters A – Z.

File Structure

• The data is the smallest unit of information stored in a computer file

• A field is a collection of related data items

• A record is a collection of related fields

• The collection of record is a file

The structure of a file in systematic order from top to bottom

•Data

•Field

•Record

•FILE

Evaluation 1. Define the following:

a) Fileb) Recordc) Field

2. List three types of data3. List the order in a file

structure