Summary
An API may have one or more versions. Each version contains API methods, and may have multiple versions published at the same time.
Consider adding new versions of APIs when changes you make impact on queries that receive your methods and/or the responses they deliver. There is no need to create a new verse in the face of minor changes.
Once you have created your API, you should create a verse using the "Create API Version" button.
Now, you should add meals to your API. Click Add Method and read the following article.

Remember that you could keep multiple versions of your API published and developer users could navigate between the different versions.
By default, the developer portal would show the latest available versions.