A moat is whatever keeps rivals from copying a company's success: a trusted brand, a network only it has, a patent, or being far cheaper than anyone else can manage.
A company with no moat can be copied the moment it succeeds, which caps how long its profits last. A real moat lets good years repeat.
A new cola can match the taste and even undercut the price, and still sell a fraction as much, because decades of brand trust don't transfer with a cheaper can.
A moat is not permanent. Brands fade, patents expire, and technology makes old advantages irrelevant. "It always held up before" is not the same as "it has a moat".
Ask one plain question about any company you follow: why can't a rival simply copy what it does? If the answer is unclear, the moat might not exist.
A moat is what stops a copycat from matching success. Ask what it is, plainly, before trusting a good run to repeat.
One line: why can’t your favourite company be copied?