What does "designated contracting state" mean in the patent?

The designated contracting parties include Austria, Belgium, Bulgaria, Switzerland, Cyprus, Czech Republic, Germany, Denmark, Estonia, Spain, Finland, France, Britain, Greece, Hungary, Ireland, Italy, Liechtenstein, Luxembourg, Monaco, Netherlands, Portugal, Sweden, Slovenia, Slovakia, Turkey and Romania.

As a member of the European Patent Convention, the European Patent Office (EPO) is an intergovernmental organization formally established on 1972. Its main function is to be responsible for patent approval in Europe. According to the European Patent Convention, a European patent application can be protected by many countries.