Unlocking and unlocking bootloader?

Is unlocking a phone and unlocking a bootloader the same thing or are they different? 

I think its a "terrorist" kind of thing where it's so genneric it can mean anything really

I don't think so, I had an unlocked phone with a locked bootloader. I was able to uninstall all the bloatware it came with but I couldn't install custom ROMs since my bootloader was locked. But I may be wrong as I don't even have a phone anymore and am way outta touch with that aspect of it. Just check out 

https://www.xda-developers.com/

They are completely different things. I bet you're thinking about the new American law that got passed where you are not allowed to unlock your phone. That only applies to unlocking your phones to another carrier than what you lock yourself into when buying a new phone. Unlocking the bootloader allows you to flash new ROMs onto the phone, it does not directly allow you to unlock your phone to new carriers.

TL;DR: Two completely different things. 

Here you go: https://www.xda-developers.com/android/thank-you-ctia-for-setting-the-us-cell-phone-market-back-10-years/

This is correct.  Unlocked Bootloader=Ability to install custom ROMs.  Unlocked Phone generally means freedom to hop from carrier to carrier (granted that the phone has the correct antennas built in for the network you're trying to switch to.)  Although sometimes it is a requirement to unlock the bootloader before unlocking the phone itself for use on other wireless services.  As posted numerous times already check out xda-developers.com and do a search for your phone model to get specific information.

Hi unlocking phone and bootloader are completly different concept .

Unlocking bootloader: Unlocking the boot loader allows you to put custom ROMs on your device.  Please note that you may void the warranty of your device and/or any warranty from your operator if you unlock the boot loader.

Unlocking phone :Its nothing but removing the network lock in mobile phone .Most phones come locked with one network provider due to this they cant be used with other network unless you unlock it .

Unlocking mobile phone can be done with the help of service providers like Superunlockcodes.com here they render code to unlock all model mobiles.