What is Ladder?
[[File:Old ladder inside Carlsbad Cavern-57.JPG|thumb|200px|Old ladder inside [[Carlsbad Caverns]]]] A '''ladder''' is a [[tool]] which is made for people to climb up or down. Ladders have two [[vertical]] supports that go along the whole length of the ladder. Between these supports are the [[horizontal]] rungs. The rung is what the climber can put his foot on. The climber can use his hands to hold on to the rungs above him, or to the supports at the side. Some ladders are made in one piece. They can be carried around and made to lean against something such as the wall of a house. There should be a good distance between the bottom of the ladder and the wall so that the ladder is not too vertical, otherwise the ladder might fall backwards and the climber would fall off. Sometimes these ladders are extension ladders. Extension ladders are made in two or more sections so that the ladder can fold up to make it easier to carry about and to store. To open up the ladder, each section slides up almost to the top of the next section. '''Step ladders''' are useful in the [[house|home]] or the [[garden]] to reach things that are not too high, e.g. ceilings or the tops of [[hedge]]s. They have two parts which are joined by a [[hinge]], so that they are shaped like an upside down V. There is usually a platform at the top to stand on, but this can be dangerous unless great care is taken that the ladder will not wobble or fall down.<ref>{{Cite web|title=Differences between household and professional garden stairs|url=https://www.megal-spb.com/press/poleznye-materialy/sravnenie-bytovykh-i-professionalnykh-sadovykh-lestnits/|access-date=|website=|archive-date=2021-10-28|archive-url=https://web.archive.org/web/20211028132232/https://www.megal-spb.com/press/poleznye-materialy/sravnenie-bytovykh-i-professionalnykh-sadovykh-lestnits/|url-status=dead}}</ref> Some ladders are vertical (they go straight up or down). These are fixed onto something. Examples are: ladders in a [[swimming pool]] for climbing in and out of the water, smal