How do touchpads handle selecting text ?

This is regarding the newly released logitech touchpad. (not the touch mouse)

I love it and considering buying one.

But my doubt is, how do you select text with it? ( for the essential function of coping and pasting text)

There is no left mouse button to hold and drag.

The video mentions that tapping the bottom right hand corner simulates a right click and tapping anywhere else is a left click. But no mention of holding the left click.

Whatever the method is, I fear it wont be as fluid as in the regular mouse.