The more common one, I think, is post hoc ergo propter hoc, sometimes just "post hoc fallacy." It's translated to, "After this therefore because of this." It's used when someone tries to establish causality even when there is no real evidence to support it.
The other one is cum hoc ergo propter hoc, which actually I've not heard of in Latin. It is translated as, "With this therefore because of this." The typical thing I hear is "correlation does not equal causation. The fallacy here is that just because two things correlate, they might not be related at all, as Spurious Correlations so brilliantly shows.
They're very similar, but differ on viewpoint orientation. Examples:
I switched from whole milk to 2% and my child scored an A on their last test after making C's.
This would be post hoc fallacy. It states that switching from 2% caused this one event. It does not posit a relationship between intake of milk and grades, though. The act of switching did that. For any child who switches to 2%, you should imagine an immediate grade boost on the text.
The more 2% milk my child drinks, the smarter he becomes.
This falls under the "correlation != causation" problem, since a relationship between drinking 2% and getting better grades is posited.
If you're charting this (no time to chart right now, sorry), the increase of 2% and the child's IQ would both increase or decrease together.
For post hoc fallacy, you should see a flat line (or so) until the act of switching to 2%, where then you should see a spike.
Hope that clarifies.