All memory cards are divided into four classes and belong to 2, 4, 6 or 10-th class. These figures are indicators of minimum recording speed provided by this card. Values are in Megabytes per second. Thus, the digit 2 in a circle on the card means that this card belongs to the second class and has a minimum write speed of 2 MB/sec. This indicator is important for a digital device performing high-speed recording or having a very large clipboard. For such devices require a memory card of the appropriate class.
The memory card of the second class the cheapest, because they have the slowest write speed. However, they are great for audio and video players, printers and photo frames. It is not recommended to use memory cards second grade photo and video cameras because these devices are designed for the active record.
The fourth class of memory card means a minimum write speed of 4 MB/sec, making this class ideal for use in Amateur cameras. Home survey - a good example of where this class is.
Write speed 6 MB/sec making memory cards sixth grade ideal for use in digital cameras average. These maps will provide enough high-quality shooting in JPEG or RAW.
Tenth class memory card provides a record with a minimum scrotu 10 MB/sec and is designed to work with expensive professional photo and video cameras. Sufficiently high price on memory cards of tenth grade due to the advanced features of these cards:

- support for Full HD video recording;
- the ability to shoot in RAW format;
- option fast continuous shooting with high quality;
- the amount of memory that extends to 32 GB.

It should be particularly noted that the function of serial shooting makes memory card class ten essential when recording different sporting events.