What is Salt bridge?

In electrochemistry, a salt bridge or ion bridge is a laboratory device used to connect the oxidation and reduction half-cells of a galvanic cell , a type of electrochemical cell. It maintains electrical neutrality within the internal circuit. If no salt bridge were present, the solution in one-half cell would accumulate a negative charge and the solution in the other half cell would accumulate a positive charge as the reaction proceeded, quickly preventing further reaction, and hence the production of electricity. Salt bridges usually come in two types: glass tubes and filter paper.