Definition (Source: Wikipedia)
***A rain gutter (also known as eaves trough, guttering or just gutter) is a narrow channel, or trough, forming the component of a roof system which collects and diverts rainwater shed by the roof. In many buildings, the purpose of this diversion is to prevent water from falling off the roof edges. This uncontrolled water can cause structural damage to the outside walls and/or the foundation of a building over time. Another purpose of rain gutter is to harvest rainwater for household or garden use.
Rain gutter can be constructed from a variety of materials, including galvanised steel, painted steel, copper, painted aluminium (also known as Seamless Aluminium), PVC (and other plastics), concrete, stone and wood.
Water collected by a rain gutter is fed, usually via a downpipe, into a collection system. A collection system can be either a rainwater tank, a storm water main, or a sewer main (depending upon local codes). In some locations where collection to a main is not feasible, the water is dispersed into a storm water pit or cistern.
Different styles of gutter are available to suit the design of the roof and house. Exterior rain gutter is available in a variety of profiles to suit the appearance of the building. Exterior rain gutter is fixed to the fascia board, which in turn is fixed to the ends of the rafters. A fascia gutter incorporates a rain gutter with a fascia. Box gutter is a deep gutter which is concealed within the structure of the roof. A box gutter is usually applied when the rainwater is to be collected from points within the boundary walls of the building. Water collected by a box gutter is fed to the downpipe via a rainhead.