A flat tire occurs when air escapes from a tire, often due to punctures, leaks, or damage. Repairing a flat tire typically involves removing the tire from the vehicle, inspecting it for damage, and locating the source of the leak. Common tools used in this process include a tire jack, lug wrench, and tire repair kit. Once the damage is identified, the repair can be made using a patch or plug, depending on the size and location of the puncture. After the repair, the tire is reinstalled, inflated to the correct pressure, and checked for any further issues before the vehicle is back on the road.