I need an elaborate answer to this question. After one of the answers I got from another question where a particular film jargon ("plotless story") was used, I read a wiki page and found that plot (narrative) means the chain of events which are linked to each other. In every show which is made for entertainment, there must be a link between events otherwise it would make no sense to watch it. Imagine a hypothetical "plotless show" where two characters completed unrelated to each other, die because of completely unrelated reasons, it'd rather be called a set of random events rather than a show.
When people say "this anime has no plot", what do they actually mean? Are they talking about two episodes not connected to each other?