1. Define input and differentiate among the program, command and user response.
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).
A computer program (also a software program, or just a program) is a sequence of instructions written to perform a specified task for a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. 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. While command is a directive to a computer program acting as an interpreter of some kind, in order to perform a specific task. Most commonly a command is a directive to some kind of command line interface, such as a shell and User Response provide small to medium size businesses and educational establishments with a vast range of Information Technology services with total commitment to high level customer satisfaction.
2. Identify the keys and buttons commonly found in desktop computer keyboards, and describe how keyboards for mobile computers and devices differ from desktop computer keyboards.
The set of typewriter-like keys that enables you to enter data into a computer. Computer keyboards are similar to electric-typewriter keyboards but contain additional keys. The keys on computer keyboards are often classified as follows:
alphanumeric keys -- letters and numbers
punctuation keys -- comma, period, semicolon, and so on.
special keys -- function keys, control keys, arrow keys, Caps Lock key, and so on.
Computer keyboard, is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. Following the decline of punch cards and paper tape, interaction via teletype-style keyboards became the main input device for computers. While Mobile computing is a form of human–computer interaction by which a computer is expected to be transported during normal usage. Mobile computing has three aspects: mobile communication, mobile hardware, and mobile software. The first aspect addresses communication issues in ad-hoc and infrastructure networks as well as communication properties, protocols, data formats and concrete technologies. The second aspect is on the hardware, e.g., mobile devices or device components. The third aspect deals with the characteristics and requirements of mobile applications.
3. Describe different mouse types and explain how to use the mouse.
Mechanical mouse: Houses a hard rubber ball that rolls as the mouse is moved. Sensors inside the mouse body detect the movement and translate it into information that the computer interprets.
Optical mouse: Uses an LED sensor to detect tabletop movement and then sends off that information to the computer for merry munching.
Infrared (IR) or radio frequency cordless mouse: With both these types, the mouse relays a signal to a base station wired to the computer's mouse port. The cordless mouse requires power, which comes in the form of batteries.
A mouse with many buttons: The extra buttons can be programmed to do specific things, such as navigate the Web or turn pages when you’re reading a document. The typical button-ified mouse has about five buttons.
Trackball mouse: Like an upside-down mouse. Rather than roll the mouse around, you use your thumb or index finger to roll a ball on top of the mouse. The whole contraption stays stationary, so it doesn’t need a lot of room, and its cord never gets tangled.
Stylus mouse: Another mouse mutation enjoyed by the artistic type is the stylus mouse, which looks like a pen and draws on a special pad.
Cordless 3-D mouse: This kind of mouse can be pointed at the computer screen like a TV remote.
Types of touch screens
Resistive
· Resistive-type screens lack the clarity of other touch screens but they tend to be very durable and can be used in a variety of environments. Resistive-type screens are the most common in use today.
Capacitive
· Capacitive screens are resistant to outside elements, making them very durable, and they still maintain a high clarity. Unlike resistive and surface wave screens, which can be used with stylus, capacitive panels must be touched with a finger.
Surface Wave
· Surface wave touch panels are the more advanced of the three types, offering the highest clarity. But they are more easily damaged by outside elements.
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