What is an ideal fluid?( Invicid fluid,Potential flow or irrotational flow characteristics)

Ideal fluid:

Ideal fluid is one that is incompressible and has zero viscosity.

Potential flow:

The fluid flow, which has zero viscosity and incompressible fluid is known as potential flow.

potential flow has two important characteristics

1. Neither  circulations nor eddies can form within the stream, so that potential flow is called irrotational flow.
2. Friction can not develop, so that there is no dissipation of mechanical energy into heat.

Potential flow can exist at distances not far from a solid boundary.