What does this line exactly represents?

Picture:
http://imgur.com/a/PpPBp

I don’t know if it is an hitpoint since I often see those line far from a hitpoint.

Thanks.

It’s a bars and beats sync marker.

I’m not sure exactly what Steinberg calls it, but they are created for every audio file you record (not import). When you move an audio file in the arrange page, it’s this marker that guides the snap to your quantise value.

Normally they appear at the very start of the audio file if you start recording from the beginning of a bar. If you do a drop in though, you’ll probably come in part way through a bar, so this will be created at the next bar line.

You can click on it and move it if you want to change its position.

It´s called “snap point”