A technical manual is a form of documentation that explains exactly how to use a product. It provides some background information, and a lot of step-by-step instructions.

A manual explains how to apply your product to solve the client’s problems.

A great manual covers every conceivable procedure that clients may encounter when using your product. It then explains every detail of that procedure, and explains each and every step required to perform the procedure successfully.

This requires great attention to detail.  Nothing can be missed out, and everything has to be both precise and accurate. No step can be left out, even if it can be assumed that some steps are obvious.

A manual must also explain what to do when things go wrong, or when a procedure does not work as expected.