As the title says, I would like to know differences between 貯金{ちょきん} and 節約{せつやく}. Both mean "saving money" and have the irregular する verb ending:
貯金する{ちょきんする} : To save money
節約する{せつやくする} : To save money
From what I understand by reading example sentences, 節約{せつやく} has a more general meaning and can be used with anything to save like water, food, money...
Is 貯金 only usable with a money context? Are there any differences between the two of them when they are used in a money context?
貯金 = to put money in the bank or a piggy bank or envelope.
節約 = to avoid spending money (i.e., to make food rather than eat out)
Both of these are [漢語]{かんご} (Chinese words in Japanese).
貯金 follows a verb-object pattern. Thus,
貯(v) store 金(object) - money
節約 follows a duplication pattern:
節(v) -save 約 - save
So you can do lots of things to 節約, but if you are talking about water, people say [節水]{せっすい} or about electricity [節電]{せつでん}. In those cases, it means "reduce use of X"
