Kinvey uses a NoSQL store on the back end, so the concepts are a little different than those of a relational database system like MySql, but in general the same thought process can apply. A Collection is similar to a table, although it is Schema-less. This means that attributes (columns in MySql terms) can be added dynamically as needed. You simply create the collection, and then start ttrockstars saving data objects to it.
For more info on our Android library specifically, take a look at our Data Store User Guide.
thanks does Kinvey support joins in Android for example if I wanted to query two collections, i haven't seen any examples relating to this in the guide.