Why were the people referred to as Israelites before they arrived in the land of Israel?

I have been reading the Torah for months since Parshiot Vayikra and in some verses, I noticed Moses refers to the Israelites or Hebrews. I’m kind of confused about the difference between Israelites and Hebrew. Are they from two different tribes? Also, why do the verses refer to the people as Israelites before Numbers and Deuteronomy?