what's the difference between these two low pass filter types
You can write their transfer function from input to the output.

The first is a active filter, assume a ideal Op amp:

$$
H(s)=\frac{-R_{2}}{R_{1}} \times \frac{1}{1+R_{2}C_{2}s}
$$

The second it's basically passive RC filter followed by a voltage follower.:

$$
H(s)=\frac{1}{RCs+1}
$$

Then, you can see some differences, such as the first one has negative gain and can have non-unity gain at low frequency.