This question should be an easy one :) I couldn't find it already in stackexchange so thought it would be worth asking.

As I understand it:

• A Maximal Matching cannot be extended (i.e. it is not a subset of any other matchings).
• A Maximum Sized Matching is if there are no larger matchings (i.e. no matchings with more edges).

So what exactly is the difference between these two? What does it mean that these two are "with respect to different partial orders"?