Answer:
to put it simply, equilibrium is when two opposing forces balance each other out. one example is boats: you know how the bottom half is curved, and then meets at an edge? they design it like that because of water displacement. by gravity, the water wants to go back to the area taken by the boats mass (the parts where it has sunken into the water), thus preventing the boat from sinking. once the boat is removed, the water returns to the space. most liquids take form of their container.