A schelling point, or focal point, is an answer that people tend to choose by default in the absence of communication or other information. The schelling point becomes a natural coordination point that people choose that can allow them to converge and coordinate their actions.
The classic example is given a random person, ask them to coordinate with a stranger to meet somewhere in New York City. The most common response picked was “noon at Grand Central Terminal” even though there is nothing particularly special about this location in terms of succeeding in the game. The key here is the reasoning about how the other player will behave and trying to pick what everyone else will do.