Military Size Vocabulary Questions

Watching the news they have been throwing out words like, battalion, regiment, brigade, platoon, squad, divisions and a bunch of others. I looked them up in the dictionary and they give just about the same answer. Here’s one for Bridgade:1 a : a large body of troops b : a tactical and administrative unit composed of a headquarters, one or more units of infantry or armor, and supporting units.
My questions is: What is required for a large body of troops to be called a bridgade, battalion, regiment etc. Is it Quantity? Type of ordnance? Is there a list that shows how this is broken down?

Between the different services, there is a wide variety of quantity of numbers. Especially when you get into the functions of the different units. An Air Force Engineer Squadron may be larger than an Army Engineer Company, but they are roughly on the same “level”. You should think of things not on a ‘numbers’ scale, but more on a tactical command scale. . .

This link

There’s plenty of threads in the GQ forum that ask this same question. Do a quick search on whatever unit type you are looking for, and read a little. You’ll see the differences.

Tripler
And we’ve got some British Dopers that explain their TOE too.