貯金 and 預金: saving and deposited funds
Compare everyday saving with money deposited at a financial institution.
Saving money
貯金 (ちょきん) means saving money or the money saved. 「旅行のために貯金しています」 says that the speaker is saving for a trip. It does not specify exactly where the money is kept.
「貯金を使って旅行しました」 means traveling using savings. Here 貯金 refers to accumulated money rather than the act of saving.
Depositing funds
預金 (よきん) refers to depositing money at a financial institution or to the funds deposited. 「預金の残高を確認しました」 says that the speaker checked the deposit balance. Checking a balance is different from saving more money.
「預金を引き出しました」 means withdrawing deposited money. This is the opposite direction from depositing, not the creation of new income.
Everyday wording and formal names
In everyday speech, money saved at a bank can also be called 貯金, so the terms are not mutually exclusive. 「貯金箱にお金を入れました」 means putting money into a savings box. Follow the stated names of actual products or institutions.
「貯金額を決めました」 says that an amount to save was decided. Distinguish setting that amount from having already accumulated it.
Does 「貯金しています」 identify which bank is used?
Show the answer and why
No. It only says the speaker is saving money; the location or institution is unspecified.