Okay kiddo, so have you ever played with building blocks before? You know how sometimes when you're building something, you need certain blocks before you can put others on top? That's a bit like how project management works.
In project management, sometimes there are things that need to happen before other things can happen. These are called dependencies. Dependencies are like the building blocks that need to be in place before you can add other blocks on top.
For example, let's say you want to build a tower out of blocks. First, you need to lay down a strong foundation so the tower won't fall over. That's a dependency because you need to have the foundation in place before you can start building up the tower.
In project management, dependencies can be things like needing a certain piece of equipment before you can start working on a project, or needing someone with a specific skill set to complete a task before you can move on to the next step.
So if you think of a project as a big puzzle, dependencies are like the puzzle pieces that fit together to make the project work. Without them, the project wouldn't be able to come together properly.
And that's a dependency in project management, explained like you're 5 years old!