Although many smartphone manufacturers have dropped memory card support, there are still plenty of handset models that offer the feature (including the Galaxy S9), and these devices are still very popular and needed. Many people buy microSD cards with only one aspect - storage capacity
There are, however, other important factors that you should take into account when making such an acquisition. Here's a brief introduction to a microSD card guide.
Does it matter
I recently changed three times a 64GB memory card that I bought with my smartphone. I tried to avoid that brand because I knew it had problems, but I did not find the 64-GB card from one of my favorite manufacturers on the day that I purchased the phone. I prefer Samsung, Lexar and SanDisk
The difference between microSDHC and microSDXC
MicroSD cards come with different storage capacities. SD Standard Capacity (SDSC) normally has between 1 MB and 2 GB. SD High Capacity (SDHC) models have a capacity of 2 - 32 GB. SD Extended Capacity (SDXC) offers 32GB of storage capacity - 2 TB
Your device (such as a DVR auto camera) might not support an SDXC card, so check it out in the user manual before you make a purchase, or look for this information on the box
Manufacturers use "speed classes" to measure the transfer speeds offered by a microSD card. There are four different standard classes: 10, 6, 4 and 2. Class 10 is the fastest and Class 2 is the slowest. Classes 4 and 6 are suitable for most smartphones, tablets, cameras, or DVR cameras. Class 10 is suitable for devices that shoot at very high resolution and can capture images in .RAW format. Class 2 cards should be avoided in modern devices. Today even the cheap smartphones can shoot in Full HD quality.
There are also two Ultra High Speed (UHS) classes - 1 and 3 - more expensive and addressed to professionals. They can be used in devices with UHS support
You will perhaps discover through the house that they do not have any symbols referring to speed. These are Class 0 microSD cards designed before the speed measurement system is introduced. Class 0 cards are slower than Class 2.
As in other areas, even here is innovation, and some companies offer models with additional features. Recently, Samsung has launched the Pro Endurance range of optimized microSDs for intensive use in car cameras or video surveillance equipment. According to the company, a 128GB microSD Pro Endurance card can record up to 43,800 hours of streamed movie content of 1,080p without risking loss of data integrity, 25 times as much as possible with an ordinary microSD card.
Samsung Pro Endurance cards are water resistant, extreme temperatures, exposure to magnetic fields and high doses of X-rays. These microSD cards can be used without problems in smartphones or tablets