The most cost-effective way to upgrade a PC is usually to swap out the RAM. If it's been a while since you last purchased computer memory, the various options available can be a little confusing. This video from TED-Ed breaks down all the random access memory essentials that you need to know about.
This five-minute clip explains everything the layperson needs to know about the language of computer memory. It succinctly covers the basics in a way even the most computer illiterate person should be able to understand, without muddying the essentials with stuff that won't affect them.
If you work in IT and are trying to get an SRAM or SSD upgrade approved, this clip could provide your luddite boss with the gentle nudge he needs.