When someone says "Force", we tend to think of pushing and pulling. Force represents the interaction of an object with is enviroment. For instace, sitting on a chair is exerting force on it. The SI unit for force is the Newton, named after Sir Isacc Newton. A Newton (N) is defined as the force that, when acting upon 1kq of mass, will produce an acceleration or 1meter/secondsquared.
If you pull a spring, it streaches, if you pull a wagon, it moves, if you catch a basketball, it stops. These pushes and pulls are called contact forces, named from the physical contact between objects.
Another type of force is a field force, and it doesn't involve any physical contact. One of the best examples of this is gravity. When an object is falling to Earth, it will accelerate, meaning the Earth is exerting a force on it. Another common example of this is the attraction or repulsion of electric charges. Like when you rub your hair on a ballon and it will attract your hair, its putting a force on your hair without touching it.