what's the difference between numpad numbers and digit numbers?

[HighKey]

I have some command shortcuts that are only working with the numbers on the numpad or only working with the numbers of the digits. Are these really different keys? Do I need two numpads, one for digit numbers and one for numpad numbers?

[suicidal_orange]

If by digits you mean the numbers across the top row with symbols on then yes, they are completely different keys to the numberpad.  If your numberpad is programmable you could put the top row numbers on a layer rather than having two, or have fun with an FN key with implied modifiers...

What exactly are you trying to do and on what numberpad?

[HighKey]

Yes, I mean the numbers 0 - 9 that are normally on 5th row of the keyboard and the numbers 0 - 9 on the numpad.

Currently I have a layer with both set of numbers on it. I am using QMK. Linux desktop window applications are layouted with the shortcut ctrl + alt + numpad, while my text editor uses "normal" digits. I changed preferences on the text editor, since this seemed easier to do.

For normal text input, both set work equally well. So I wonder on which applications does it make a difference? Should I keep both sets or can I get rid of one of them?

Also, I don't want to use num lock, is there a way to permanently lock it?

[suicidal_orange]

If you set number lock to 'on' on startup you can remap the num lock key to do something useful, and use the LED for something else too.  Not really permanent but if you can't toggle it it's pretty close.

Number pad numbers are good for holding Alt Gr and getting random characters or holding shift to use their secondary legends (arrows, home, end...) but if doing things like spreadsheets having currency symbols and the % sign handy could be good too.  99% of the time if you just want to write a number there is no difference so just depends what you're doing in the last 1%

[suicidal_orange]

A thought I had while at work - are you aware just how customisable a programmable board is?

For example you could have the numbers as numberpad numbers and remap Num Lock to be an = if you tap it, but if you hold it it's an FN and on that layer / * and - could be the number row keys 1, 2 and 3 with whatever mods to switch tab in the text editor.  Then you could have 0 if you tap or hold it then all the number keys becoming shifted versions of the number row keys so you can use the symbols.

I'm sure it can be done in QMK but I've always prefered EasyAVR so won't be able to help unless you can use that (it doesn't do RGB LEDs or ARM controller chips)

[VP]

For Alt codes numpad numbers work, numbers on 5th row do not work.

[HighKey]

For example you could have the numbers as numberpad numbers and remap Num Lock to be an = if you tap it, but if you hold it it's an FN and on that layer / * and - could be the number row keys 1, 2 and 3 with whatever mods to switch tab in the text editor.  Then you could have 0 if you tap or hold it then all the number keys becoming shifted versions of the number row keys so you can use the symbols.

we don't talk about how much time I took to understand this sentence (we don't!). 
I totally like the idea to have the symbols in a number grid 

For Alt codes numpad numbers work, numbers on 5th row do not work.

that is quite useful to know - didn't know that, thank you!