Shutter lag is the time between your pressing the shutter button and the moment the camera actually snaps.

and two doors of fir wood the two leaves of the one door were folding, and the two leaves of the other door were folding.

And the two doors were of fir tree the two leaves of the one door were folding, and the two leaves of the other door were folding.

Shutter speed is critical to catching motion, thus sports photography is often done in shutter priority mode or manual.