chalkboard

A chalk board is a large, flat, dark, slightly abrasive surface on which you write using chalk, which is a material that crumbles easily and hence rubs into the irregularities of the board, producing lines. The advantage to chalk boards is that they are easily erased using a felt eraser.

Some people are allergic to chalk dust, so they use a whiteboard instead. Chalk boards are commonly found in classrooms, meeting rooms, and other places where a topic being dicussed can be described with drawings.

An older medium for writing stuff on. They come in many colours, grey, green, black, brown. You can write on them using chalk, which is just a solid stick of something, which when rubbed, gives off pigmented dust. They are commonly used in classrooms, lectures, and meetings. However more and more of them are being replaced by Dry Erase boards, or white boards.

They generally come clean with a special eraser, which just smears the dust around and takes most of it off, however every so often (depending on use) it needs to be wiped down with a wet rag or sponge to get rid of the excess dust.

As much as i like white boards (having asthma and all, dust bad), there is still something about seeing a complex equation or proof take shape on a chalk board by someone who is really smart.