Conservative forces are forces, where the net work done in a round trip is 0. For e.g., gravity. If a body is lifted and dropped by height 'h', then net work done by gravity is mg(h-h) = 0.
However, non-conservative forces are forces, which are not conserved. i.e, in a round trip, the net wok done is not 0. Common examples of such forces are friction and induced electricity.
For your benefit, almost all other types of forces are conservative, apart from the 2 mentioned above. Also, conservative forces have the concept of P.E (potential energy) associated with it, whereas P.E for a non-conservative force is undefined