Microsoft_office_2021_ltsc_(x86)_v2108_build_14...

Dynamic Arrays, XLOOKUP, and LET function support for more complex data handling.

Perpetual (One-time purchase, no subscription).

The x86 version is 32-bit, designed for maximum compatibility with older plugins, macros, or legacy 32-bit Windows systems.

The between this build and the 64-bit (x64) version? How to activate it using KMS?

Here is a detailed overview of the or similar builds within the 2108 release. What is Office 2021 LTSC?