OpKey Web allows you to create your account & experience awesomeness of test automation free within the trial period. Once trial period is over, you are required to purchase license to further use OpKey. For details about Account registration, refer this link OpKey Account Registration.
OpKey has two types of License one is Seat License and Second one is Concurrent or Floating License.
Seat License: Seat License is a Computer bond or Node locked License. It is tied only for one machine in which you have installed your OpKey. Seat License is different for OpKey Web, OpKey Execution Agent and Plugins
Concurrent License: Concurrent or Floating License is a Network based License. In this type of License, multiple users can use same Concurrent License for OpKey Web, OpKey Execution Agent and Plugins.