M1 money is more liquid and floating money and spent everyday.
Think like this Savings money could be potentially investing money and may not exchange hands as frequently.
Travellor's check - When you buy travellor check you pay money and the cash is exachanged between the hands (from you to issuing institution) but not with normal checks until the receipient of the check deposits to the bank and it clears.
M1 money also excludes the Government checking accounts.