What is difference between force and load?

Answer 1

It is all about context.


Let's talk about a clothesline.

The load on the clothesline is the weight of all the clothes hanging from the clothesline.
That load is one of the forces on the line.

Each end of the clothesline is attached to something; the clothesline pulls on that thing, and that thing pulls with an equal and opposite force on the clothesline.
That pull is another one of the forces on the line.
The force of that pull is often many times the force of the load of the clothes.

There is also the small force of gravity acting on the mass of the clothesline itself.
That force is another one of the forces on the line.

On some days, the wind pushes directly on the line, and indirectly on the clothes hanging on the line.
That "wind load" is another force on the clothesline.

Many students taking classes in statics learn about the internal forces on ropes such as this clothesline.
They imagine cutting the line, holding the cut ends with their hands, and try to figure out how hard they would have to pull to keep it in the same place that it was before the cut.
In other words, they are trying to figure out the internal pull of one part of the rope on the other part.
These students learn about many kinds of internal (non-load) forces, such as tension, compression, torsion, bending moment (torque), etc.
In ropes, such internal forces are always in tension, but other (non-rope) structures have all these other kinds of internal forces.