The EL of a problem is the measure of difficulty on coaching actuaries. Every problem has its own EL that depends on how often it is solved correctly/incorrectly by people using coaching actuaries. Exam P and Exam FM, which I’m assuming you are studying for one of, anecdotally have been polled to contain problems ranging about 4-6 EL on the coaching actuaries scale. When you are taking an EL 5 practice exam for instance, all the problems will have an “average” of EL 5. You may see EL 3 problems and you may see EL 7 problems, so long as the average is 5. But on the actual exam you most likely wont see problems easier than a 4-4.5 and you wont see problems harder than a 6-6.5.
Edit: in terms of your own EL (earned level) its just an arbitrary way to gauge the EL of exams you are likely able to pass, I wouldn’t pay too much attention to it and just focus on problems/quizzes/exams in the 4-6 range.