I wnated to understand the difference between testcases and tests. In the problems given on codeforces , is it so that every test has several test cases inside it ? And the time limit mentioned in the problem is the time limit under which all the test cases must pass or is the time limit under which a single test case must pass ? And one more thing , in the submission section , is the execution time mentioned , the maximum time taken by the program I submitted ?

Please clarify ?