Savings as such I consider as just having cash at home and money in an account, usually a bank savings or deposit account. Cryptocurrencies are an investment, and precious metals are an investment as well, although many people consider them savings. Perhaps gold would be in a grey area, as it does not have large price fluctuations and is usually easily convertible to cash, but I would only consider it savings in the medium term at least, because unless you buy very large amounts, it is not worth buying today to sell next week, as you will lose money because of the premiums to be paid.

In short, savings are best in a remunerated account in the bank or deposit and/or cash at home, depending on taste.