When do you need to use a differential lock?

It has become the must-have inclusion for every serious four-wheel drive, but when and why do you need to use your differential lock?It’s the little button marked with an ‘X’ and an axle, usually positioned near the gear shifter that most suburban drivers will never use in the life of their car – still, we all love to know that we have that buttonRELATED: I took a 2025 Isuzu MU-X off-roading, and it blew my mindBut why do you need a differential lock? And when should you