The claims of a patent create the extent of protection sought in a patent application. A set of elements or noun phrases with specific character and designated limitations are used for writing claims in a patent application. These are of utmost importance as prosecution and litigation point of view.

A patent is an exclusive monopoly right (negative right ) granted to the patentee restraining others from making , using , selling, offering for sale the patented subject matter defined by the mechanism of claims. The scope of a claim is important because the scope differentiates the claims from the prior art and state of the art of the said technology and limits over broadening or narrowing down the claim to protect from any infringement prior art or novelty issues.

A patent application needs necessarily at least one claim for the invention defining the primary subject matter and elements of invention with utmost care and criticality.  The basic parts a claim are:-

1. A pre-amble reciting the class of the invention
2. A transitional phrase
3. The body

The language for drafting claims should always be precise and contain some certain words commonly used e.g. “comprising”, “consisting” etc, but he meaning of these words could be different.
Depending on the structures of the claims in a patent application, the claims can be categorized in two groups:

(a) Independent Claims
(b) Dependent Claims

Moreover, there are other special types of claims depending upon the languages used viz.

1. Beauregard claim
2. Business Method Claims
3. Jepson Claims
4. Markush Claim
5. Means Plus Function Claims
6. Omnibus Claims
7. Product-By-Process Claims
8. Swiss-Type Claims