What is the different between "Make" and "Build" in context menu of project build configuration?

• Build compiles all source files in the project.
• Make compiles those that have changed since the last make or build.

Note that make is actually a little more complex. A unit, let us say unitA, can require re-compilation during a make even if unitA has not changed. This happens when unitA uses another unit, unitB, and the interface section of unitB has changed since the last make or build.

The documentation for Build states:

Rebuilds all files in your current project regardless of whether they have changed. Building is useful when you are unsure which files have changed, or if you have changed project or compiler options.

The documentation for Make states:

Compiles only those files that have changed since the last build, as well as any files that depend on them.

Make compiles outdated modules (the ones that were changed since the last project compilation), while build (re)compiles all modules.