Reuse is a way of recycling but the reason that reuse is better than recycling is that when you reuse something you do not need to use any more energy or resources to reuse the product that is already made.
When you recycle something such as metal or plastic the metal or plastic needs to be melted down and then turned into the new product before you can use it.
You also need to factor in the cost of transportation and the fuel to transport those recyclables to the recycling plant to melt it down as well as the energy to melt the metal or plastic downs.
If you are able to reuse the metal or plastics without melting them down then you save energy and can just reuse the item.
For example I go to a scrap yard and buy some used steel that is already formed but still good enough to weld on or use.
It's much better to use that metal already made in the form required for my project than to go buy new metal that has been melted from old metal that used more energy.