Adverbs are words that modify verbs, adjectives, or other adverbs. Adverbs of degree are used to show the intensity of something. When used to show intensity of other adverbs, adverbs of degree only show the intensity of gradable adverbs, and not all adverbs are gradable, for example, entirely, absolute, immensely, uniquely, etc, are not gradable. In other words, intensity shows the difference between slowly and very slowly. The word slowly is an adverb that describes the speed at which something is done, and adding the adverb of degree very tells us that this is intensely slow!
One adverb of degree is absolutely. You will use this to emphasize something is wholly or completely the case. For instance, this sentence explains that the person really needs to do his homework!
You have to do your homework! This is absolutely true!
The adverb almost tells us something different. This adverb tells us that something is not quite something else; it is very nearly something: almost finished, almost full, almost blooming, almost round.
Wow! I found almost enough of it.
This means the person did not find everything needed, but nearly all of it, most of it.
The word extremely means "to a great degree."
The bear ate extremely hungrily.
The bear had a great degree of hunger! The adverb extremely modifies the adverb hungrily.
The adverbs entirely and completely mean similar things: "in every possible way" and "to the greates degree possible." We use them to show that everything is meant, or just the opposite when we add the word not.
My computer is not entirely operating dependably.
You can see how adverbs of degree can be used to describe other adverbs to add intensity to meaning very efficiently!