What does 'through/before' mean here?

There is a little difference between them:

  • "through" means "until and including"
  • "before" means "until" without including

For example,

  • through 4.10.15: versions before 4.10.15 and version 4.10.15
  • before 4.10.15: versions before 4.10.15

The meaning of "before" is usually in terms of numerical order. However, it is advisable to read the Linux kernel versioning