hashtables and handles

Can someone explain to me the benefit of using a synchronized hashtable object and provide an example where its use would be neccessary? Also, could someone explain the lock statement a little better than MSDN's poor attempt? Also, could you use the lock statement in an example and explain to me how or if this relates to syncronized hashtables? Also, can i lock an unsyncronized hashtable? Can I lock ANYTHING? I ask this as I've been writing my first large C# program and it seems to be leaking handles of some sort, althought I can't figure out how it could possibly be leaking anything. When using process explorer, an awful lot of what process explorer calls "events" are present, unnammed events that is. Are these considered handles? Even the definition of handle on the MSDN site appears to be only partially correct if this is true (not surprising). Thanks in advance