There are different names of Shree Jagannath (or 'Sri Jagannath' or 'Shri Jagannath'), which are generaly used by people, 'Puranas' and 'Vedas'. The names of Shree Jagannath represent the activity, nature, characteristics of the Lord.
Jagannath was called "Purusottama" since his origin at Puri or ‘Purusottam Kshetra’ (the abode of Purusottam) since pre-historic times. The Rig Veda refers to him as the ‘Daru’ (sacred log of wood) of Purusottama, afloat on the eastern sea. The name "Jagannath” (Lord of the Universe) is invariably a collective representation of the Triad (Jagannath - Balabhadra - Subhadra) and has been in use since the dawn of the last millennium.
Different names of Shree Jagannath :