expression, ichidan verb
save money; put money aside
General expression for accumulating money, often by setting aside a portion of income or reducing expenses.
毎月少しずつ金を貯めている。
I save a little money every month.
旅行のために金を貯めたい。
I want to save money for a trip.
貯金する specifically means to deposit money in a bank or savings account, while 金を貯める is a broader phrase for accumulating money, not necessarily in a bank.
Phrase composed of 金 (money) + を (object marker) + 貯める (to save, accumulate). The verb 貯める is a transitive ichidan verb meaning 'to amass' or 'to store up'.