" Simchat Torah means "Rejoicing in the Torah." This holiday marks the completion of the annual cycle of weekly Torah readings. Each week in synagogue we publicly read a few chapters from the Torah, starting with Genesis and working our way around to Deuteronomy. On Simchat Torah, we read the last Torah portion, then proceed immediately to the first chapter of Genesis, reminding us that the Torah is a circle, and never ends.

This completion of the readings is a time of great celebration. There are processions around the synagogue carrying Torah scrolls and plenty of high-spirited singing and dancing in the synagogue with the Torahs." (Source)