Why does the Panama Canal use locks?

The Panama Canal utilizes locks primarily to navigate the varied topography of the region and the differences in ocean levels.

A mountain range runs the length of Panama, including through the area where the canal was constructed. To traverse this terrain, the canal was designed as a high-level waterway that lifts ships to the elevation of Gatun Lake, which accounts for approximately half of the canal's total distance.12

The locks function as water elevators: they raise vessels from sea level to the height of the inland lakes and subsequently lower them back to sea level on the opposite side. Additionally, the locks are necessary because the tidal levels of the Atlantic Ocean and the Pacific Ocean differ, making a simple sea-level passage impractical.1