Please pardon my ignorance...

I'm invited to the wedding of one of my grad school classmates on Sunday. The invitation reads:

Kabalat Panim at five o'clock
Chuppah at half past six o'clock
Dinner following Chuppah

The Chuppah is the wedding ceremony, right? What is "Kabalat Panim?" Are the guests supposed to show up at five? 6:30? Some time in between?

Inquiring minds want to know...