Where I come from, we usually consider investing in stock(funds) and rent(funds).
I am now speculating, since I don't speak Norwegian - but German is somewhat close and has similar financial terms:
What you call
"rent funds" are actually bond funds. Here in Germany, they are called "Rentenfonds" or "Anleihefonds". I guess in Norwegian, the equivalent would be "Rentefond". All of these are just different terms for a bond fund.
The easiest differentiation between stocks and bonds is the role in a company's balance sheet and the distribution of returns.
- Every stock holder is a (partial) owner of the company. Stocks pay out dividends and you can benefit from the
- Every bondholder is giving a (partial) loan to the company. Bonds have usually a fixed duration, pay a fixed interest rate and are paid back @ 100% nominal value at the end of the fixed duration (in case the debtor is not bankrupt)
Role of bonds in the portfolio:In most US-based portfolios, bond funds of debtors with high creditworthiness (investment grade bonds) are used as the more
stable/secure part of the asset allocation. In most European countries it makes currently more sense to allocate the stable/secure part of the asset allocation to a ladder of current and fixed deposits with a trustworthy direct/online bank - as these often have a higher yield and are protected by the local deposit protection scheme and thus eliminating the risk of the bankruptcy of the debtor (If I interpret this correctly, there is also one in Norway up to NOK 2mn per customer,
https://www.bankenessikringsfond.no/deposit-guarantee/category949.html).