Travel can be community teams or open selection (tryout or invitation). The teams can be in a league or play tournaments. How far a team travel depends on the need. When I ran a team from 13u to 16u USSSA was 45 minutes away. Within 90 minutes was Sports at the Beach (CABA), Ripken and Diamond Nation (Cust). 17u/18u teams are typically regional or national to provide the players the right college exposure.
When my son was nine and ten he played community travel in the summer after his spring rec league. Travel was LL and Ripken all star teams. At eleven and twelve he played in a USSSA AA Sunday doubleheader league concurrently with LL. All stars went into August both years. From thirteen to fifteen he played USSSA Majors tournament ball. We had teams from several states coming to our area. At sixteen and seventeen he played on a travel team that traveled the east coast providing college exposure.