Alongside means next to or beside something, running parallel to it. When two boats float alongside each other in a harbor, they're side by side, close enough that you could step from one to the other. When a bike path runs alongside a river, it follows the same direction as the water, staying near the riverbank.

The word often suggests movement or progress together. A teacher might work alongside students on a science project, meaning she's participating with them, not just watching from across the room. When a new employee learns alongside an experienced worker, they're together in the same space, doing similar work.

You can also use alongside when comparing or listing things together. A book about World War II might discuss military strategy alongside stories of ordinary people's experiences. In this sense, alongside means the two topics appear together and are given equal importance.

Whether it's physical position, like walking alongside a friend, or a more abstract pairing, like studying math alongside science, the word creates a picture of two things sharing space, direction, or attention.