Noobie question; Moving along an axis

If you are trying to get a vertex or a face to move along just one axis while editing a model, is there a way to do it without the scroll wheel?

I thought I got it to do so once, but I’m not sure how. In that case a group of colored arrows matching the axis arrows appeared inside the object. If I clicked on the arrow it could be dragged in the direction (positive or negative) of the arrow only. Does anyone know how to get to that mode?

In the 3D view window, at the bottom, click on the picture of a hand button.

Vertex or face, in Edit Mode, first, select the elements you want to move. Press hot key “G” to grab. Press hot key X, Y, or Z for axis of movement. Than just drag with mouse or inter distance.