On Passover, we break the matzah as a symbol of the "poor man’s bread" that the slaves ate in Egypt. There were various degrees of slavery. Some lived under better conditions, some worse. What this means is that some had access to food and some did not. Those that did, broke their bread and shared it with others who had less, hence the term “poor man’s bread.”
This is symbolized by the act of breaking the matzah in half at the Seder,