system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:the difference between a singer and a vocalist.

My so called musically inclined friends say there is a difference between the two. Suposedly a singer sings in tune and with the music, while a vocalist is like a screamo or rock singer who instead just lays their vocals over a track. I dont fully trust their info. But if this is true then what would a rapper be?
gpt
A singer is someone who sings.

A vocalist is an umbrella term. It could be a singer, a rapper, or a screamer. You only say "vocalist" when you're referring to someone in a band or ensemble that involves other musicians. 

For example, it would be weird, but not incorrect, to say that Lady Gaga is a vocalist. She is, but she doesn't really perform with other musicians. She's just her own artist.