Standby mode will leave the DB in restoring mode,writes are not allowed but user can connect and give select statements.

restore database adventureworksLT
from disk=’c:\backup\adventureworksLTfull.bak’with replace,
standby =’c:\backup\adventureworksLT ful.stn’

With recovery mode will ensure that no more restore will happen and DB will be online.

restore database adventureworksLT
from disk=’c:\backup\adventureworksLTfull.bak’with recovery

With norecovery will ensure more restore can happen,like restoring differential or Tran_Logs.

restore database adventureworksLT
from disk=’c:\backup\adventureworksLTfull.bak’with norecovery