What is difference between voltage and current?

Voltage . . .
The 'pressure' between two points that makes electrons 'want' to move from one of the points to the other one. More pressure is called more 'volts'. This can determine the brightness of lights and the speed of electric motors.

Current . . .
the flow of electrons between those two points, IF there's something in the space that the electrons are able to flow through. More current is called more Amperes (or 'amps').

The amount of current depends on how strong the voltage is, AND on what the electrons are flowing through in order to get across the space. (That's called the 'resistance' between the two points. Resistance is measured in 'ohms'. More ohms means it's harder for the electrons to get across the space, and the result of that is ... less current.)

It's also worth pointing out that current is only a flow of electrons in (mainly) metal conductors. In other conductors, such as electrolytes, a current is a flow of ions (charged atoms) rather than electrons -sometimes different types of ions flowing in opposite directions to each other at the same time. A more general definition of current, therefore, would be 'a flow of charge carriers'.