Let’s be honest do you like to do product documentation if you ask same question to me then my answer will be No always, documentation is a lengthy and tedious task which no one likes. Product Documentation is preparing a document for the product which includes of all information about the product in stepwise. Documentation usually comes at various stage of project life cycle where it is necessary to build such documentation, some time it is called reference of what you are creating or easy way to understand what you are creating. Even though you do not like do documentation but it is a vital part of product involving computer software, about 20 to 40% of time is taken in preparing such documentation under project life cycle.
Documentation should be such that it gives precise information about the product for which documentation is done.