Comep321L IT Concepts & SAD

1. Input is the term denoting either an entrance or changes which are inserted into a system and which activate/modify a process. It is an abstract concept, used in the modeling, system(s) design and system(s) exploitation. It is usually connected with other terms, e.g., input field, input variable, input parameter, input value, input signal, input port, input device and input file (file format).
Input may refer to:

• Advice (opinion), an opinion or recommendation offered as a guide to action, conduct.
• Information, any data entered into a computer or data processing system, see input output
• The act of entering data into a computer or data processing system (see Input/output).
• Input device, any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system (such as a computer)
• Stimulus (physiology), a detectable change in the environment that influences an activity of an organism
• Power consumption, an amount of power used by a system.
• International Public Television Screening Conference, an international public television organization
• In economics, a factor of production, a resource employed to produce goods and services.

Computer program- is a sequence of instructions written to perform a specified task for a computer.^[1] A computer requires programs to function, typically executing the program's instructions in a central processor.^[2] The program has an executable form that the computer can use directly to execute the instructions. The same program in its human-readable source code form, from which executable programs are derived (e.g., compiled), enables a programmer to study and develop its algorithms.

Commands- come in different forms. They can be:

special words (keywords) that a program understands.

• function keys

choices in a menu

• buttons or other graphical objects on your screen

Every program that interacts with people responds to a specific set of commands. The set of commands and the syntax for entering them is called the user interface and varies from one program to another.
The DOS operating system makes a distinction between internal and external commands. Internal commands are commands, such as COPY and DIR, that can be handled by the COMMAND.COM program. External commands include the names of all other COM files, as well as EXE and BAT files.




2. A desktop computer is a personal computer (PC) in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer.
Desktop and tower computers are two different styles of computer case that use desk space in varying ways. Desktop computers are designed to lay flat on the desk, while towers stand upright.
Prior to the widespread use of microprocessors, a computer that could fit on a desk was considered remarkably small. "Desktop" indicates a horizontally-oriented computer case usually intended to have the display screen placed on top to save space on the desktop. Most modern desktop computers have separate screens and keyboards.
Tower cases are sometimes incorrectly called desktop computers as some will locate them on a desk instead of on the floor under the desk. Cases intended for home theater PC systems are usually considered to be desktop cases in both senses, regardless of orientation and placement.



3. Different mouse types*

1) Mechanical: This is a type of computer mouse that has a rubber or metal ball on its underside and it can roll in every direction. Sensors within the mouse, which are mechanical, detect the direction in which the ball is moving and moves the pointer on the screen in the same direction. A mouse pad should be used under the mouse to run on.
2) Optomechanical: This type is the same as the mechanical mouse except that it uses optical sensors to the motion of the ball. A mouse pad should be used under the mouse to run on.
3) Optical: This type uses a laser for detecting the mouse's movement. You don't need a
mouse pad but you can use one made for optical mice. Optical mice do not have any
mechanical moving parts. This type responds more quickly and precisely than the mechanical and optomechanical mice and now that they have been around awhile the price is pretty comparable.

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