Computer input devices are external devices used to send task-specific information to computers. Such devices provide an interface between the user and the computer and are used to perform different functions.

The keyboard is probably the best-known computer input device. However, there are several other examples of these peripherals, such as mouse, touchpads and joysticks.

Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions (called program) and gives the result (output) and saves output for the future use. It can process both numerical and non-numerical (arithmetic and logical) calculations. 

The basic components of a modern digital computer are: Input Device, Output Device, Central Processing Unit (CPU), mass storage device and memory. A Typical modern computer uses LSI Chips.  

Four Functions about computer are:  

accepts data Input

processes data 

produces output

Output stores results Storage  

Computer is an electronic device which is capable of receiving information (data) in a particular form and of performing a sequence of operations in accordance with a predetermined but variable set of procedural instructions (program) to produce a result in the form of information or signals.

Actually it's not Mode...it's MOD means Modulus(%) which is used to demonstrate the remainder of a particular division and MOD(%) with Like query in MySQL is used to determine a value of any length....

While Underscore is this symbol(_) which is used with Like query in MySQL to determine fixed length of a value..

Got it??

Ans. Any information that has been processed by and sent out from a computer or similar device is considered output. A simple example of output is anything you view on your computer monitor.

To gain 90+ % in Class 12th, one has to do a lot of self study. Practice previous year question papers in every subject. Clear your doubts. Refer NCERT thoroughly and practice all the important concepts in every subject. If you are able to score +85 marks in every subject, you will have a good percentage in the end.

But write now,just focus on your exams not on marks. Start the final revision of every subject. All the best!