In brief and In essence

In brief adverb - In a concise manner; in a few words.

In essence and in brief are semantically related. in in short topic. In some cases you can use "In essence" instead an adverb phrase "In brief".

In essence adverb - With regard to fundamentals although not concerning details.

In brief and in essence are semantically related. You can use "In brief" instead an adverb phrase "In essence".