Some other apps call them regions too. Vegas calls them events, some apps call them clips
What makes it real fun is the Vfire support in reaper, so the roland vstudio guys use reaper and the terminology gets all weird for them...one of these days we will all speak the same language
there's a few ways, none of the default ones seem very satisfactory for those used to working that way, so Bevoss made some macros on the reaper forum to download for the host behaviour you want