The 4R means Reduce, Reuse, Recycle and Restore.
(i) Reduce: We should reduce the use of non-biodegradable compounds that are harmful to us.
Example: Instead of using polythene bags we should give preference to paper bags.
(ii) Reuse: We should reuse the materials instead of dumping them.
Example: Plastic bags can be reused to make decorative things.
(iii) Recycle: Non-biodegradable materials should be subjected to the recycling process.
Example: Plastic materials.
(iv) Recovery: If the waste remains after it is been reused and recycled, we can use it to generate energy at our waste-energy plant. This is known as Recovery.