The flow of electric charge carriers in a conductor or semiconductor is called an electric current.
In conductors or semiconductors, electric current is conducted by the tiny particles. These tiny particles are known as electric charge carriers.
The electric charge carriers could be electrons, holes, protons, ions etc. However, the electric current is often conducted by electrons and holes.
In conductors, holes are negligible. So electrons conduct electric current. In semiconductors, both electrons and holes are present. So both electrons and holes conduct electric current.
Electric current is an important quantity in electronic circuits. When a voltage is applied across the conductor or semiconductor, electric current starts flowing. Electric current is often referred to as “current”, for simplicity.