What exactly does "backdoor" refer to?

In the context of smart contracts, a "backdoor" is not necessarily the hidden entry point found in malicious software, but specifically refers to the centralized control privileges retained by developers.
Most ordinary retail investors understand the concept, but their awareness is vague or they ignore it.
Most people have "heard of" the risks associated with smart contracts, such as exit scams, and know that security audits are important.
However, their actions lag behind: in practice, due to lack of technical knowledge, temptation from high returns, and FOMO (Fear of Missing Out) psychology, many do not personally verify audit reports, or even know where to find them. They often rely on "community consensus," "big V recommendations," or the reputation of the project team to make decisions.
· Selective trust: They know in theory that backdoors exist, but believe that "this star project / project listed on major exchanges should be fine."