Real estate crowdfunding: what is the difference between lending and owning a share?

In lending (debt) projects you lend to the developer at an agreed interest rate. Interest is usually paid monthly or quarterly, and your principal comes back at the end of the term. The property often serves as collateral, which reduces the risk, but you can still lose capital if its value does not cover the loan. You have no control over the project.
In equity projects you become a part owner rather than a creditor. You receive a share of rental income or profits, plus a gain on sale or exit, in proportion to your stake. Returns can be higher but are more variable, and you can lose your entire investment. Investors usually have less control than with direct ownership, sometimes with voting rights.
In short: lending gives more predictable income with the property behind it; equity gives more upside with more risk. Capital is at risk: crowdfunding investments are not covered by deposit guarantee schemes, can lose part or all of their value, and may be hard to sell before the end of their term.