sim vs region?

[Lucia TopHat]

This is probably a stupid question, but what is the difference between a full or whole sim and a region? 

[Innula Zenovka]

Strictly speaking, according to the wiki, a region is simulated by a sim process (software) which runs on a sim node or sim host (hardware).

In practice, though, most people use "sim" to mean "region".   However, if you spend much time talking to technical Lindens or the Land team, you soon learn not to.

[Rolig Loon]

Technically, a "simulator" is a computer software package that runs on one of Linden Lab's servers, managing all of the basic functions for a region (or up to four 256 m X 256 m regions) of virtual real estate in SL.  In practice, most people use the word "sim" -- a contraction of "simulator" -- to refer to the server that the program is running on, and then also use it as a synonym for "region".  If you want to be very careful, though, you can make points with purists by using the words sim, server, and region properly. 

Read http://wiki.secondlife.com/wiki/Server_architecture#Simulator