Is agile different than SDLC or is agile an SDLC?

I am not sure how the two are different and I see different things about how many phases are in SDLC. It seems like SDLC can be used to explain how an organization develops software. I see some say SDLC is a waterfall framework for methodologies with 5 phases. But then I see SDLC has 6 phases, then some say 7, then I see SDLC can also be agile.

Does SDLC fit into the picture like this? Where Waterfall is an SDLC, and something like Scrum is an Agile methodology but still fits under an umbrella of SDLC?

->SDLC

————–> Waterfall

—————> Agile

—————————–> Scrum

—————————–> DevOps

—————————–> Extreme Programming

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I guess I am interesting in knowing what is and isn't SDLC, and what can and cannot be described as an SDLC?