Bearer Token
In plain terms
An access token granting whoever holds it access.
Going deeper
A bearer token is presented in requests to prove authorization; possession alone grants access, so it must be protected. Holding it means access.
Under the hood
Sent as 'Authorization: Bearer <token>'; short lifetimes and HTTPS limit theft impact.
Examples
OAuth access tokens, API authentication, JWT, Authorization headers.
Think of it like...
Like a concert ticket, whoever holds it gets in, so don't lose it.