This is a strip of 20 crimp pins. You can use a pair of needle-nose pliers and a soldering iron to attach these pins to your wires. Then you can insert them into one of these polarized housings: The picture below shows an attached wire about to be inserted into the 2-pin housing:
The housings then will plug into their matching headers:
Use these combinations in your designs for any interfaces where you want to ensure that the user does not connect them the wrong way.