A manual is a publication that includes the essence of a subject. It is a guide that helps to understand the functioning of something. Furthermore, the user is the person who uses classically something or recipient of a service.
These two definitions allow us to understand what is a user's manual. This type of publications provides the necessary instructions so that the user can use an any product or service. For example, if the user manual is a mobile phone, it will contain explanations of its operation, the functions of the buttons, options, etc.
That said, a user's manual, operating instructions, was a technical communication document that is designed to help those who use a system. In addition to their specificity, the textbook authors rely on accessible and simple language to reach the largest possible number of receivers.
Given their complexity, all electronic and computer products have their own user manual. Other simpler products (such as a ball or a table) require no manual so the user knows how to use.
The user manuals are written in several languages and include both texts as images. Thus, the understanding of concepts is made easier. Diagrams and drawings are also common.
A common structure of the user manuals includes a target product introduction, a table of contents on the contents of the manual, the guide itself, a section of common problems including explanations on commits resolve, contact information and a glossary.