What’s the difference between the TEF and the TCF for Canada immigration?

You can also answer the difference between IELTS and CELPIP if you please. It seems to me the difference between the language tests is one is proof that you speak the language fluently, like if I came from France to Canada, I would have to prove my French fluency. I’m more interested in the French tests and I’m pretty sure you only have to take one test of either French or English. The other test is for those who do not speak a language but have learned in during the immigration process and to prove they learned it.