Deploying code is known by multiple names on the mainframe - the customization and use of each is quite site-specific.
The entire range of source management and configuration management may be part of "code deployment". The mechanics used are quite different from site to site. Some organizations use 2 tiers - test and prodution. Some use development, test, user acceptance, production, and an "emergency repair" tier.
In all of these, code is written/changed at the lowest level and then "promoted" to the next level (unless dealing with an emergency on a system that provides an emergency repair environment).
This is not like Windows and Visual Source Safe or Team Foundation Services, though many of the goals are similar.
Hope this helps,