How to understand the margin of safety in investment?

In fact, I've been thinking about this issue for many years, and I haven't understood what Buffett means by the margin of safety, but I finally realized this is how cheap a company I don't understand is not cheap. My understanding of the margin of safety is the understanding of the company rather than the short-term stock price fluctuations. For a great company, sometimes a little price difference may not be a problem after 10 years, but it may be a big deal to miss a good company because of that price. $TENCENT(00700.HK)$ $BABA-SW(09988.HK)$ $Tesla(TSLA.US)$ $Twitter (Delisted)(TWTR.US)$ $AMC Entertainment(AMC.US)$