That means you can cross from one to another. The states are next to each other.
Maine.
Maine
line
Illinois and Missouri border one another, and therefore, there is no state in-between them. However, both Illinois and Missouri border the state of Iowa.
All states border another state except for Hawaii and Alaska.
Border, boundary of frontier.
All states but Alaska and Hawaii border at least one other state. Maine is the only state to border just one state.
Maine, it shares a border with Vermont.
Maine
A border, state line , county line, etc.
Every state borders another except Alaska and Hawaii. Alaska does, however, border Canada; while Hawaii is an island. The continental state with the least borders is Maine, at one state, while the states with the most border states are Missouri and Tennessee, at eight states.