This topic describes some terms you may need to know as you use this publication.

Migration

Activities that relate to the installation of a new version or release of a program to replace a previous level. Completion of these activities ensures that the applications and resources on your system will function correctly at the new level.

Coexistence

Two or more systems at different levels (for example, software, service or operational levels) that share resources. Coexistence includes the ability of a system to respond in these ways to a new function that was introduced on another system with which it shares resources: ignore a new function, terminate gracefully, support a new function. These are examples of multisystem configurations in which resource sharing can occur:

• A single system running multiple LPARs
• A single processor that is time-sliced to run different levels of the system (for example, during different times of the day)
• Two or more systems running separate processors
• A Parallel Sysplex configuration (also includes a basic sysplex)