ELi5: SD card speeds


So i’m in the market to purchase a new SD card for my phone, and i’ve tried researching how the speed classes on them work, but it’s a bit confusing. Such as the classes, the markings (C10, U3, V60 for example)

I’m basically just needing an SD card that is capable of playing 1440p video without lagging any during playback, transfer speed isn’t too important. What are some things that I should look out for, and what should I avoid?

In: 4

What is the bitrate of this 1440p video? 1440p video can be anywhere between 2 Mbps and a few hundred Mbps depending on its compression and accompanying audio track(s). Is this a video taken on a phone or a proper camera?

All these classes of SD card only indicate write speeds. Read speed is USUALLY greater than that. But even if it weren’t, let’s say if an hour of your video takes up less than 36 GB, you’ll be fine with cheap old class-10/UHS-1/V10 card which guarantees sustained write speed of 10MBps.