latch phase

'search phase' and 'latch phase' refer to the two stages in homing.

'search phase' : Machine moves at 'HOME_SEARCH_VEL' speed until it activates the switch and then backs off the switch again.
'latch phase': Machine moves at 'HOME_LATCH_VEL' speed (usually slower then in the 'search phase' to increase accuracy) until it activates the switch and sets the home position.

So 'phase' in this context has nothing to do with the electrical phase, just in case the translation is confusing you.

Yes, the difference is speed. The latch phase is with much lower speed for better accuracy.

I noticed that you have already another thread here forum.linuxcnc.org/49-basic-configuratio...configuration#219570
about the same topic.
Please avoid opening more than one thread on the same topic, it makes answering questions really confusing.

Thanks