It is common for a body to be always subdued to the action of two or more forces. These can be clasified, according to its direction, in concurrent and parallel.
It is said that two or more forces are concurrent when the direction of its vectors are cut at one point at least. Otherwise we would be talking about non concurrent forces or parallel forces.
The main difference between concurrent and non concurrent forces is that if they are exerted over free bodies, the first ones can cause translation movements (the body moves to somewhere else), whereas the second ones can do rotational movements (the body turns).
Remember that we will work with the approximation of point particles (bodies that have all the mass concentrated at a single point) on this level. This means that wether there is more than one force exerted on it, they must necessarily be concurrent forces and they can be added.