Reduce means to use a material/commodity in lesser quantity, e.g., electricity and water. Recycle means a material that is used once is collected and sent back to a manufacturer so that they can make some other useful material from it.
e.g., plastic cups and buckets, glass tumbler, paper, metal objects.
Reuse means using a thing over and over again : instead of throwing it away. It does not involve the process of recycling either in small or large scale, e.g., used envelops, plastic carry bags, bottles of jam.