The Saxons were a Germanic tribe who settled in England and North Western France. The Saxons were one of three tribes which later became known as Anglo-Saxons.
To quote Bede:
These new-comers were from the three most formidable races of Germany, the Saxons, Angles, and Jutes. From the Jutes are descended the people of Kent and the Isle of Wight and those in the province of the West Saxons opposite the Isle of Wight who are called Jutes to this day. From the Saxons - that is, the country now known as the land of the Old Saxons - came the East, South and west Saxons. And from the Angles - that is, the country known as Angulus, which lies between the provinces of the Jutes and Saxons and is said to remain unpopulated to this day - are descended the East and Middle Angles, the Mercians, all the Northumbrian stock (that is, those people living north of the river Humber), and the other English peoples.
The term "Anglo-Saxon" refers to the Angles, Saxons and Jute tribes of Germanic origin which invaded Briton in 5th and 6th Centuries.