Defining an R/3 Instance

When you hear someone say the word instance, most of the time, that person will be referring to an application server. The term instance is synonymous with application server.

The term central instance refers to the database server. If an application server and database server both reside on the same machine, the term central instance refers to the computer on which both reside.

In the most general terms, an instance is a server. It is a set of R/3 processes providing services to the R/3 system.