I need some help with instagram?

[696]

When people comment to others on posts its say (i'll use and example)

I agree @something

@something is blue and i can click on it and go to their page. How do I do that? I can't figure it out! Thanks

[Morgan]

That's tagging someone.
Let's say I want to tag Jamie on a cool pic of a cat(random)
@jamie hai look at this fat cat
they get a notification you tagged them.

[Julie]

All you have to do is type "@" and then their username