In computing, a loader is a program that performs the functions of a linker program and then immediately schedules the executable for action, without necessarily creating an executable file as an output. Loader programs are useful for prototyping, testing, and one-off applications.
In heavy engineering equipment, a Loader is a type of tractor, usually wheeled, that uses a bucket-like shovel in order to dig dirt and load it onto trucks. The loader is capable of doing both small carrying tasks (moving cement blocks or earth) and small bulldozing tasks.
Large loaders, such as the Caterpillar 966G, usually have only a front shovel (then called Front Loaders), whereas small loader tractors are often equipped with a small backhoe (then called Backhoe Loaders).