Question about 'user process' in the context of Oracle

The following is an excerpt from Oracle's documentation : > When a user runs an application > program (such as a Pro*C program) or > an Oracle tool (such as Enterprise > Manager or SQL*Plus), Oracle creates a > user process to run the user's > application. As per my understanding, a user process is a piece of software that can connect to an Oracle server. You (the user) can start this piece and then connect to Oracle. If so, why does Oracle create a user process to run the user's application?