How does 'Convert to ANSI' and ANSI Encoding function work in Notepad++

What is the difference between function 'Convert to ANSI' and selecting ANSI character set for a file? 

Let's start with an example; ᒋ Inuktitut symbol for 'gi'. The hexacimal representation of ᒋ is e1 92 8b opened in FRHED a free hex editor.

The 'Convert to ANSI' actually reduces the character set to fit within the ANSI range of 0-256 characters. ANSI encompasses on the upper end the Latin-1 Supplement plane to handle some established European languages. 

So, characters greater than decimal 256 or 0x3f in hexadecimal are converted to a question mark (?).

When you 'Convet to ANSI' on gi, it became a question mark 0x3f in hex. In Notepad++ you see a question mark as well. 

Select Encoding -> ANSI, does not change the values, just how they are displayed in Notepad++.