From books online:

ON { | filegroup | "default" }

Specifies the partition scheme or filegroup on which the table is stored. If . If filegroup is specified, the table is stored in the named filegroup. The filegroup must exist within the database. If "default" is specified, or if ON is not specified at all, the table is stored on the default filegroup. The storage mechanism of a table as specified in CREATE TABLE cannot be subsequently altered.

If you specify a partition scheme then table will be called partitioned one.

Data will be switched out only for the partition that you will specify under Alter .... switch statement rest will remain there at source.

MJ