The output of your command "snap --help" is:

The snap command lets you install, configure, refresh and remove snaps.
Snaps are packages that work across many different Linux distributions,
enabling secure delivery and operation of the latest apps and utilities.

Usage: snap  [...]

Commonly used commands can be classified as follows:

           Basics: find, info, install, remove, list
          ...more: refresh, revert, switch, disable, enable, create-cohort
          History: changes, tasks, abort, watch
          Daemons: services, start, stop, restart, logs
      Permissions: connections, interface, connect, disconnect
    Configuration: get, set, unset, wait
      App Aliases: alias, aliases, unalias, prefer
          Account: login, logout, whoami
        Snapshots: saved, save, check-snapshot, restore, forget
           Device: model, remodel, reboot, recovery
     Quota Groups: set-quota, remove-quota, quotas, quota
  Validation Sets: validate
        ... Other: warnings, okay, known, ack, version
      Development: validate

For more information about a command, run 'snap help '.
For a short summary of all commands, run 'snap help --all'.