Help me popularize science. What are dental inlays and gold inlays?

Hello, if you go to the local dentist, you can make inlays according to your actual requirements. What kind of teeth are better? What kind of crown is better here, because if it is a complete denture or an implant denture, it is another way of saying it. There are generally several kinds of cheapest metal crowns, namely, nickel-chromium and cobalt-chromium crowns. The corresponding materials are cheaper, but there may be some risk of pigmentation. In the upper stage, that is, the metal crown of pure titanium or gold foil, the compatibility of these two crowns will be much better, but it also contains some metals. The all-ceramic crown mentioned on the internet has no metal, which will not have any influence on the image inspection, but it will have the risk of porcelain collapse. What needs to be said here is that the more expensive the crown, the better.