A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a very long period of time. Some valleys are formed through erosion by glacial ice. These glaciers may remain present in valleys in high mountain or polar areas. At lower latitudes and altitudes, these glacially formed valleys may have been created or enlarged during ice ages but now are ice-free and occupied by streams or rivers. In desert areas, valleys may be entirely dry or carry a watercourse only rarely. In areas of limestone bedrock, dry valleys may also result from drainage taking place underground rather than at the surface. Rift valleys arise principally from earth movements, rather than erosion. Many different types of valley are described by geographers, using terms that may be global in use or else applied only locally.An institute is an organisational body created for a certain purpose. They are often research organisations (research institutes) created to do research on specific topics. An institute can also be a professional body, or an educational unit imparting vocational training—see Mechanics' Institutes. The word "institute" comes from a Latin word institutum meaning "facility" or "habit"; from instituere meaning "build", "create", "raise" or "educate".
In some countries, institutes can be part of a university or other institutions of higher education, either as a group of departments or an autonomous educational institution without a traditional university status such as a "university Institute" (see Institute of Technology). Also, private schools are sometimes referred to as institutes—rather than schools—in some other countries, such as South Korea and India. In Spain, secondary schools are referred to as institutes.