These two phrases mean almost the same thing, but it can be useful to know the difference. Making peace with something means you “become resolved or reconciled.” Coming to terms with something means you “accept or become resigned” to it. It can also mean to reach an agreement. Make peace with is usually used to talk about humans. Come to terms with is usually used with non-living concepts.
Living versus Inanimate
To make peace with and to come to terms with both operate like a transitive verbs. Transitive verbs describe the action of a sentence, and are always in relation to a direct object. The object of make peace with is more likely to be a person. For example, imagine a pair of neighbors arguing daily over one of them playing their music too loud. One day, one of them decides she’s had enough of the fighting. She makes peace with her neighbor, and they’re able to negotiate a compromise about the music.
The object of come to terms with is usually an inanimate object. If in the music scenario the neighbor stops fighting and just accepts the loud music, this means she’s come to terms with it. It’s not wrong, but it’s much less common to hear that someone has “made peace with loud music” or “come to terms with their neighbor.”
In some cases, to come to terms with someone can literally mean to agree on specific terms with them. The phrase still usually refers to a non-living thing. If the neighbors come to terms with each other about music volume, these terms might include how loudly music can be played and at what times.
The title of Jess Ainscough’s health and lifestyle book, Make Peace with Your Plate, is an example of using make peace with with a non-living object. In this case the plate symbolizes diet and lifestyle. Because the plate is personified (given humanlike qualities), it’s appropriate to say make peace with.
Make peace with and come to terms with should each be preceded by a subject and followed by a prepositional object. If he is the subject and her is the object, you could say, “He makes peace with her,” or “He comes to terms with her.”