What is Patent Classification

What is Patent Classification?
A Patent Classification is a code used to categorize an invention. Classification are typically expressed as "482/1". The first number, 482, represents the class of invention. The number following the slash is the subclass of invention within the class. There are about 450 Classes

of invention and about 150,000 subclasses of invention in the USPC.Classes and subclasses have titles which provide a short description of the class or subclass. Classes and subclasses also have definitions which provide a more detailed explanation. Many Classes and subclasses have explicitly defined relationships to one another. Subclasses contain patents. In a sense, classes also contain patents but for classification purposes patents are always classified at the subclass level. That is one or more classifications (i.e., class/subclass designations) are assigned to each granted patent and each published application.
Why is classification so important?
While it is possible to search patents using keywords, the best way to conduct a comprehensive patent search is by Classification. By determining the Classification of an invention you eliminate any ambiguity that terminology may create.
Please consider if something is truly new a common term (or name) does not yet exist. For example, before personal computers a mouse was nothing more than a rodent. Thus, having invented the first "Computer Input and Display Control" one would not be able to search for keyword "mouse."By determining classification you are able to search a group of patents that are similar to the one you are research. This makes it easier to determine patent infringement.
A classification is used both as a tool for finding patents (patentability searches), and for assisting in the assignment of patent applications to examiners for examination purposes.
Classifications have definitions.
Classifications have hierarchical relationships to one another.