Commit changes at deadline or during a maintenance window (requires restarts)
In short, SCCM 2012 has a tickbox when configuring an application for install that tells clients to commit changes at deadline or during a maintenance window.
This setting is for thin client PCs that use write filter technology only. This allows you to install things on the thin client then commit the changes later. If changes are not committed, they are lost when the thin client restarts.
Ticking Commit changes at deadline or during a maintenance window (requires restarts) means that the install will be commited to the thin clients memory when it restarts or during a scheduled (in SCCM) maintenance window. If you have no maintenance windows scheduled, my understanding is that it won’t commit the changes.
If you do not use thin client with write filters, you can safely ignore the Commit changes at deadline… setting.
If you are using thin clients with write filters, then I recommend that you do some testing with this setting before pushing applicatons out to your entire organisation, to ensure you get the desired results.