This photo shows an older edition Macintosh SE/30 logic board, which had gold-capped, socketed 68030 CPUs. The newer boards have soldered in CPUs.
Some contend that these older "socketed" boards are more valuable because some accelerator upgrades were once available that fit into the CPU socket. However, I myself in many years of search EBAY have yet to see one of those boards. Nevertheless, I now own a socketed SE/30 logic board that would make such an upgrade possible.