An insurance policy is an agreement between the policy holder and the policy provider. It states that the provider will pay out if a particular situation is dictated by the policy at hand. Therefore, as long as the policy holder has paid the agreed premium, they will cover the costs associated with that situation. Insurance Cover in the UK
One way of looking at this is that it provides peace of mind, allowing people to own possessions or hold things dear to them without needing to worry about what they would do should they be taken away from us in some way.
If this takes the form of a vehicle insurance policy, for example van insurance, then all those owning a van will have obtained the policy, with it being a compulsory policy to obtain before heading out on the roads.
A lot of people these days use a service that allows you to compare van insurance and the different levels of cover and special offers are visible in an list saving your lots times search for a great deal.