According to the author of the book of Exodus, this verse tells us that the Israelites were moving from one place to another on their way out of Egypt. They stopped at a place called Etham which was near the desert.
Exodus 13:20: And they took their journey from Succoth, and encamped in Etham, in the edge of the wilderness.
This verse states that the Israelites left Succoth and camped at Etham after encamping at Succoth, providing a similar account without contradiction.
Numbers 33:6: And they departed from Succoth, and pitched in Etham, which [is] in the edge of the wilderness.