What does the message "Time Limit Exceeded" means?

I would like to know what is the meaning of this message. This is my first time competing and I am fresh here. Please need guidance. Thanks

Time Limit Exceeded (known as TLE) means that your program failed to finish executing before the established time limit for the problem.

Also note that this time limit is only valid for 1 input fileā€¦ All programs are judged against several input files, which may contain 1 or more test cases.

So, if Time limit is 1 sec, and your program runs correctly on 30 files, taking 0.5 sec on each file (0.5 <= 1), you will have accepted solution with execution time of 15 secs.