What’s the use of RSA signature

Can any one explain me what’s the use of RSA signature , and is it required for laptop repairs ?
And what’s the role of modding it ! As we get directly from the exe file we download from the respective companies website the bios files !

It’s used to stop BIOS manipulation, sometimes only at the “Flashing” level, other times inside the BIOS. There is no modding it, sometimes you can bypass it when used either way, but not always.

In simple words it not needed in for laptop repair as far!!!
am i right as its already integrated by the oem manufacture .

Yes, this is not something “You” as a user/fixer etc would integrate, it’s either there by default from manufacturer or not.
It can get in your way trying to fix something though, if you have to edit BIOS before programming, to fix the BIOS by putting in user serial or UUID for example, then it can brick system

ok thnx for your feed back!!