A microscope slide holds a sample, usually biological, for viewing through a microscope.
There are several common varieties of microscope slide. Slides are almost always glass, but vary between thin and thick varieties. While most slides are flat, some have concavities to better contain samples, usually numbering between 1 and 3.
Microscope slides don't differ very much from brand to brand: they're a fairly standard lab supply. What's key is price, which is why we aim to provide the best pricing possible for this key consumable.