solenoid or relay switch
It could be, a dead battery, loose or dirty battery connections, a faulty starter,
If you are talking about a car engine and battery then it is not the battery that is clicking. It is in all probability the solenoid.
Your battery is not giving enough power to start the car. It may be battery, alternator, voltage regulator or bad cables.
you need a new batt.
i need help with my car
jump start the car and get a new battery and if it isn't the battery it could be the alternator or both, but try a new battery first
Bad battery, starting motor or both.
ITs your Starter
your battery is either lose or dead check that
battery or corroded connection on battery One click most likely is a bad starter motor or solenoid. Many clicks battery or connection problem.
i might be wrong but it could be the 'bendex'. this is the part of the starter motor that disengages it after the engine turns on. it might not be fully disengaged from the previous trip. sometimes all that is needed to get it to go is to rock the car foreward or back a little. hope that helps.