system
Given the following post, respond as if you're commenting on Reddit:
human
How does adaptation (in evolution) work?

So the way I understand evolution is that mutations happen and those mutations turn out to be better in given conditions (and as a result animals without that advantageous mutation die off). But then adaptation comes into play. How do they occur? I reckon one individual doesn't just decide they need larger paws or better vision and just get it. How do bodies adapt through time if not by mutations? Thanks.

EDIT: Thank you all for all the answers. I knew where to ask. Cheers!
gpt
What you're thinking about is actually two sides of the same coin. The way natural selection works is similar to what you say. Lets take Giraffes. In some ancestral Giraffe, there was a population of individuals, some had longer necks and some had shorter necks. Ultimately, the ones with the longer necks had better access to resources (in this case food from trees). The longer necked Giraffes tended to have more offspring, that had longer necks, and slowly the shorted necked individuals died out. Thus, now all our Giraffes are longer-necked. The main thing here is the natural selection can only act on traits that are already present in the gene pool. 

Now the term adaptation generally means, a trait that has been evolved to do something. When we look at Giraffes today, it would be acceptable to say, longer necks are an adaptation for feeding, which they are. Depending on who uses the term in what context, an 'adaptation' may both refer to the trait that has evolved and/or the process by which it has evolved. 

Mutations specifically refer to a change in DNA. Mutations can be good, bad, or neutral. Mutations are the only way that new traits can evolve. But as you point out, just because some trait might benefit an animal (like better vision for instance), does not mean it will ever evolve, or that a mutation for that will ever happen. The mutation must already be present in a population of individuals, and then if that mutation is beneficial, then maybe natural selection will act on it. Meaning the individual with the mutation will ultimately make more offspring than other individuals.