Crimping is a way of terminating strands of wire in order to connect them to external circuits, using a crimping tool to squeeze a wire hard enough to cold weld it to a given terminal. Crimp terminal kits consist of a crimping tool and various types of terminal.
The advantage of crimping is that it forms gas-tight connections, so there is less corrosion of the wire, and the joints are mechanically strong as there is no additional material used, as opposed to soldering.
There are broadly three steps to using crimp terminal kits:
Crimp terminals can have different connectors, such as rings, spades, and butt splice terminals, depending on how you want to connect to the external circuit. There are also insulated and non-insulated terminals, depending on your price point and the needs of the circuit. Non-insulated terminals are cheaper but may short in certain environments, whereas insulated terminals protect against this.