The Valuation Cap is often referred to as the "Valuation" of the business; however, that's only partially true.
Valuation Caps are the implied MAXIMUM that the investor and founder agree is the value of the company - the value can be lower if a future funding round is priced below the valuation cap.
Both SAFEs and Convertible Notes often have Valuation Caps - although some SAFEs and Convertible Notes don't have valuation caps, it's fairly rare.
Can I have different investors with different valuation caps? The easy answer is Yes.
Investor Can Get a Lower Price than Valuation Cap
At the conversion, the Convertible Note or SAFE will generally convert into equity at a valuation no higher than the valuation cap, but if the value comes in below that (what is referred to as a “down round”) then the original investment will convert at the lower value.
This way the investor ensures the best price for themselves.