What do you understand by System Documentation?
Ans.: Documentation is any communicable material such as text, video, audio, etc., or combinations thereof used to explain some attributes of an object, system or procedure. It is often used to mean engineering documentation or software documentation, which is usually paper books or computer readable files such as HTML pages that describe the structure and components, or on the other hand, operation, of a system/product. You probably immediately think of printed training manuals when you think of "documentation" but there are several different forms for different occasions.

Characteristics of Good Documentation :

Clear : Able to be understood by whomever it was created for. The language used must be appropriate Terms that may not be understood by everyone need to be explained either the first time they are used or in a glossary.
Concise : It should be as short as it can be while still being comprehensive. Using pictures can replace hundreds of words and be much clearer at the same time.
Complete : It should not leave out important information especially key steps that need to be completed, such as printing, and warnings about what not to do.
Current : It's no use if all the facts are out of date or superseded. Printed material is harder to keep current than electronic versions are.
Correct : It must not contain errors.
Easy to Access : It must be available where and when it is needed.
Easy to Search : Users must be able to quickly find the required information. Indexes or tables of contents are required, along with clear headings. Large documentation may well need to be divided into sections.
 

Types of Documentation :
Printed : The traditional format for documentation, it is used much less now days. Printing is expensive and books are heavy and bulky, which increase transportation costs. Books are hard to keep up-to-date if their subject matter is subject to change. Books can only be accessed by one person at a time.
Onscreen Help : Most programs come with online help that can be accessed immediately by user. It is readily accessible, searchable and can be very detailed. Help can also be gained from online sources such as the internet and intranets. Such sources can easily be kept up to date - even on a daily basis. They can be accessed by any number of people simultaneously.
Audiovisual : Videos, screen movies, audio narration etc. are colorful and engaging but do not tend to carry a lot of detailed information. These types of documentations are good for introductions or overviews of subjects.
Posters, Leaflets : Sometimes detailed information is not needed. A checkout chick, for example, does not need wiring diagrams for the circuits of the register. User may just need a little poster that quickly reminds her how to do basic tasks.