Almost all cameras use removable memory cards to store photos and video. A few smaller devices use fixed in-built memory instead, but these are relatively rare. Memory card types Memory cards come in many different types, though many have slowly been phased out and others are very specialised. The most common type is the SD/SDHC/SDXC […]
Class rating (memory cards)
SD/SDHC/SDXC memory cards are given a 'class' rating to indicate how well suited they are to video capture, where a minimum sustained write speed is essential. Lower spec cards may have a Class 4 rating, better cards may be Class 6 and you need a Class 10 card or better for capturing 4K video.