...interpreting this as just a code snippet that focuses on your question,
e is a variable of type TimeoutException being specified as a parameter to your catch clause. If code running earlier in a "try block" happened to take a TimeoutException, a TimeoutException object would be instantiated, initialized and the catch() handler would receive that object as "e". The single line in the handler, e.printStackTrace(), calls the method printStackTrace() in the exception object. This causes the object to print a stack trace ( a way to "walk back" through the method calls that got you here... ) to the console. According to the API, it prints this stack trace to standard out.
SCJP - 86% - June 11, 2009