It’s ridiculously easy, these days, to get lost among the different types of memory cards on the market. All new phones come with a memory card slot and each have their own compatibility issues.
There are 6 major types of memory cards that you should know about: SD, miniSD, microSD, SDHC, miniSDHC and microSDHC.
SD (Secure Digital) cards were among the first cheap memory cards to be sold. They were released in 1999 and are now becoming obsolete. This card can hold a maximum of 2GiB.
MiniSD cards came right after the SD card. For the 2 years after its release, it was the most popular memory card. The must have among geeks. These cards had the same maximum capacity as the SD cards.
When the first microSD card was released, it was a real revolution. For its 11 mm x 15 mm size could hold 4 GiB of data. These cards proved to be conveniently sized for phones, which were getting thinner and thinner at that time.
The SDHC card looks exactly the same as the SD cards. But their capacity are in two leagues, since the SDHC card can hold up to 64 GiB of data. This is an enormous amount considering the size of the card. SDHC also has faster speeds of transfer.
The miniSDHC cards can hold up to 32 GiB of data. They share the same dimensions with miniSD cards, but offer faster speeds of transfer.
MicroSDHC cards are similar to microSD cards physically. MicroSDHC cards can hold much more data and have faster transfer speeds. These cards can hold a maximum of 32 GiB of data.
You should note that while SDHC and SD cards share the same size, devices supporting SD cards do not necessarily support SDHC cards. However, devices supporting SDHC cards do support SD cards.
Sometimes, microSD cards are sold with a miniSD or SD skeleton. This means that you can plug the microSD in a slot in the bigger card. Be aware that it is not 2 separate cards.
Memory cards are fragile, never buy them second hand. They are very cheap commodities, so buying a new one will be more profitable.
Be aware that there are a lot of memory card imitations sold. Buy from a trusted buyer.