As requirements for higher capacities came in, SD cards have grown in capacity too (SDHC is SD High Capacity, while SDXC is SD Xtended Capacity). SDHC cards typically come in capacities between 4GB to 32GB. Backwards compatibility is built in, so if a camera has SDHC support , it will support standard SD cards too.
Considering this, what is difference between SD and SDHC cards?
SDHC is the same physical size and shape as standard SD but meets the new SD specification of version 2.0. If the SD card is 4GB or above, it is classed as a SDHC card. Currently, SDHC specifications allow for memory cards of a capacity between 4GB and 32GB.
Do Micro SDHC cards work in microSD slots?
All microSD cards fit into all microSD card slots, but they won't all work. microSD: Has a capacity up to 2 GB, and can be used in any microSD slot. microSDHC: Has a capacity of more than 2 GB and up to 32 GB, and can be used in hardware that supports either SDHC and SDXC.