A Hot Shot load is where someone drives a regular pickup truck usually and pulls a large enough trailer to haul a large load that a regular semi driver doesn't want to haul.
Sometimes a large load may be better suited for a hot shot driver to haul with a pickup and large trailer than to hire it out to a semi truck who may charge more.
Some large pickup trucks are able to easily and safely haul some large loads that you would think need a Semi Truck to haul.
You can usually have something hauled by a hot shot driver cheaper than a semi would deliver the load.
You usually do not require a CDL to be a hot shot driver and haul hot shot loads unless your vehicle weighs 26,001 pounds or more or you're hauling any hazardous waste.