What you have there is some "Salvaged Junk". There are a few things you can do with it.
1st: Recycle it. You can do this yourself, or find an experienced recycler to do it for you, possibly at a cost. When recycling, you need to use a Recycling Processing Unit (RPU) (classified as a Cargo Expander). Each recycling unit has a base "Item Efficiency" (found in its description). You can help boost this efficiency by raising your "Refining" skill. You can not got above 100%.
Dock at a location that has a Commercial Storage (a Commercial Storage Transport Service might also be a good service at the location), have the RPU equipped, go the Misc part of your ship's storage and use the green button to start recycling. Each piece of junk has a pre-set list of resources it will yield and a maximum amount (which you can gain with 100% efficiency). The resources will be put in the local Commercial Storage.
2nd: Sell it/use it for an NPC mission. Just like you would any other item. For detailed information, refer to the specific FAQ entry.