Archives: Theory

Data Storage Capacity

Data storage capacity is the measurement of how much data can be stored in a storage device. Bits and bytes Data storage capacities are measured in bytes, where each byte is actually a pattern of 8 bits….

Output Devices

What is an output device? Output devices are pieces of computer hardware used to communicate the results of data processing performed by a computer. The objective of output devices is to turn computer information into…

Input Devices

What is an input device? Input devices are peripherals used to provide data and control signals to a computer. Input devices allow us to enter raw data for processing. There are many examples of input…

Primary Key

A primary key is needed to provide a unique way to identify one record (row) from another within a database table. Fields marked as a primary key will not allow duplicate entries in that field…

Database Table

A database table (sometimes called a file) is a collection of records about the same entity (topic). Some databases contain just a single database table (called a flatfile database) whilst others may have many tables…

Database Record

A database record refers to a collection of fields about the same person/item/object. A database record can be thought of as a row of information within a database table. Example: Student Table First Name Last…

Database Data Types

Database data types are the attributes that specify the type of data that a field can hold. Why bother? It’s important to specify the right data types for your database fields because the computer needs…

Programming Data Types

In programming, data types are the attributes that specify the type of data that an object can hold. We need to declare a data type for variables and arrays. Why bother? It’s important to specify…