Permissive licenses permit a broader range of use compared to “copyleft” licenses.

“copyleft” here just being a cute way of being the opposite of copyright - instead of disallowing others from what they can do with “copyrighted” code, “copyleft” requires that they (upon request) share modifications to your code.

Permissive takes away this requirement to share your modifications. “copyleft” is considered more free and open source (FOSS), permissive is more business friendly.

You can substitute “at least 10 years ahead” as stated in the second sentence of the article quoting US senators.