Creating contexts in the studio is described in the recipe Adding contexts to a context group in Chapter 6, Managing Context Variables.
This is the simplest method of managing contexts. It all takes place in the Studio and is very visible to the developer.
It is also is a reasonably good way of protecting an environment, because when the code has been deployed, the context variables and launchers in production are usually available only to operational personnel. This means that the values available to a job in production, for example, passwords, can only be set in production by operation staff and will never be known by other personnel.
The number of contexts can easily get out of hand and become ...