ASR 1001-X router upgrade, about the filename

[Chin Chang]

I planning upgrade ASR 1001-X router, current version is 16.12.04, it will upgrade to 17.06.04 .
I noticed those bin filename, include
「noli」
「npe」
「npe_noli」
I want to know what they means?

https://software.cisco.com/download/home/284932298/type/282046477/release/Bengaluru-17.6.4