Using the example of Siloe Patera caldera on Mars.

There are two depressions (could represent two different eruptive episodes) with steep sided walls, collapse features and low topographic relief. 

Morphology of impact craters include features such as a central peak, uplifted crater rims and ejecta blankets surrounding them. There are three impact craters surrounding Siloe Patera that exhibit the three features listed above for impact craters. 

Note that a central peak does not need to be present in an impact crater. The morphology and the size of an impact crater depend on the impact energy.