Why the inside door lock button work on a 1998 Chevy Suburban?

The inside door lock button on a 1998 Chevy Suburban works because it's connected to a mechanism that operates the door latch. This mechanism is usually a simple rod or cable system that's mechanically linked to the locking mechanism itself. When you press the button, it actuates this rod or cable, releasing the latch and allowing the door to open from the inside. It's a purely mechanical action, unlike the power locks which use electricity.