Latkes are potato pancakes prepared for Hanukkah, a Jewish holiday that in addition to other things, celebrates the 'miracle of light'. This refers to the fact that after the Maccabee Jews defeated the Greek Syrians and came back to light the Menora of the Temple in Jerusalem, there was no more pure olive oil to be found, except for a small amount that ended up miraculously lasting for eight days (until more could be found/processed).
Because oil is part of the miracle, oily foods tend to be eaten as a symbol. Latkes are thus potato pancakes made with oil.
Latkes are potato pancakes, often served as part of the Jewish Hannukah celebration. Some people like them with sour cream, but I prefer mine with a little butter and applesauce.
Latke is a Yiddish word that means pancake. During Channukah, most people eat potato latkes but personally, my favourite are wild rice and mushroom latkes.