Module connectors
PV modules are installed outdoor and exposed to the elements, therefore any connections made with PV modules should be water-tight. PV modules are typically connected to one another, or to a wire that goes to a combiner box, with specialty connectors designed for use with PV modules exposed to water and sun. These connectors are designed to be crimped onto wires using a specialty crimper. They can then be easily snapped together, but typically require a tool to separate them once connector to avoid accidents.
Modules can come with different types of connectors - MC4 (the most common type of connector which is produced by Staubli), Amphenol, Tyco - which are not compatible with one another. So it is important to make sure that you have the correct type of connector to be able to make a connection with the PV module. Otherwise a high resistance connection can be created that might lead to a failure or a fire. It is also important that a crimping tool designed for use with the specific type of connector is used.