What are the differences between the access modifiers public and internal in the context of programming?

In programming (for example, in Swift for iOS), access modifiers define the visibility and scope of code elements:

• public — accessible from any module or file. This is the most open level of access, allowing the class, method, or property to be used anywhere in the project or even outside of it.

• internal — accessible only within the current module (for example, an app or framework). This is the default access level in Swift, which restricts code usage to the boundaries of a single module.

Thus, public allows an element to be used everywhere, while internal restricts it to within the module, helping to encapsulate implementation details and control the API.