How to Define a Line in Three Dimensions?

How do you describe a line? First of all, i guess that's a good question to address. A really easy way to describe a line in three dimensions is to just pick a Vec vector. Doesn't matter what the length of it is,. All that matters is the direction. And again, this is all im burning back to the intuition of it. Unless for chance that te jus sev mlaly missing something.