A patent is a monopoly or an exclusive registered right for a specific period of time (typically 20 years subject to the payment of prescribed renewal fees) in exchange for a full disclosure of the invention to the public. This disclosure should be sufficient to enable somebody of reasonable competence in the field to put the invention into practice. The monopoly entitles a patent holder to enforce the patent against others. After expiry of that period of time or earlier lapsing of the patent, the public is free to use the invention.
The full disclosure of the invention to the public is made in a patent specification which includes written claims to stake out the extent of the monopoly claimed.
A patent protects innovations with novel, useful and non-obvious applications.