The term “patent searching” can often lead to confusion because it can refer to several different types of search. Two of the most common types of patent search are the patentability search (sometimes called a prior art search or an invalidity search) and the freedom-to-operate search (also called an infringement search). The differences between these two types of patent search are often misunderstood.
In a nutshell, a patentability search is aiming to establish whether a patent can be (or should have been) granted for a concept by looking for existing disclosures (often, but not always, patent applications) which show that the concept is known or obvious; conversely, a freedom-to-operate search considers whether one or more features fall within the scope of any granted patents in the specific country/countries of interest.
Key to this is the point that a granted patent does not give you freedom to operate. The value of a patent is that it enables you to control the market for products or processes within the scope of the claims; it does not confer freedom from infringing third party patents. By way of explanation, imagine a person who was the first to invent a bicycle having multiple selectable gears. They do a patent search and find that no-one has suggested the idea before. They can readily obtain a patent and monopolise bicycles with multiple selectable gears. But when they try to sell their product they may find that they infringe an earlier patent for the whole idea of a bicycle; or for the mechanism used to make the chain; or the material used to make the wheels… so patentability and freedom to operate are quite different things and obtaining a granted patent or a licence to one only helps you if it enables you to monopolise a product or process of commercial value.