According to Wikipedia, the Jutes were a Germanic people, believed to have originated from Jutland (which was called Iutum in Latin) in modern Denmark and from part of the neighbouring coast of East Frisia.
The Jutes, along with the Angles, Saxons and Frisians, were mentioned in Chronicles amongst the Germanic tribes who sailed across the North Sea to raid and eventually invade England and Scotland from the late 4th century A.D. onwards, either displacing, absorbing or destroying the native Celtic peoples there.
According to Bede, they ended up settling in Kent, Hampshire and the Isle of Wight. There are a number of toponyms that attest to the presence of the Jutes in the area, such as Ytene, which (Wikipaedia, citing Florence of Worcester as a source) states was the contemporary English name for the New Forest.
Doubts were expressed over Bede's accounts, but archaeology has countered these, and established that a cultural group did pass from Jutland to Kent and the Wight. That they then disappear, as a separate force, from Englsih history has been put down to the greater strength of the West Saxon kingdom(s), which conquered and absorbed their Jutish cousins.
Hengest and Horsa are thought to have been their (probably mythic leaders, invited in initially around 450CE as mercenaries, by Vortigern, the "proud tyrant", and allowed to settle on the Kentish Isle of Thanet. In fact, Hengest may well have been an Anglian, since they were overlords to the Jutish peooples, and it is likely that members of all three Germanic tribes in fact settled in Kent, but that the main Angle and Saxon colonies were elsewhere in England, leaving the Jutes with only their south-coast settlements.
Canterbury became their principal capital in Kent, and the Kentish kingdom lasted until 825CE, when it was absorbed by Wessex as a dependency, finally being extinguished in 860CE when Aethelbert took the West Saxon throne.