Street Art is a very broad concept. Actually almost everything what We can call Art and what is outdoor is Street Art.
Ok. I'ma bad definer... Lets look what Wiki says:
Street art is any art developed in public spaces — that is, "in the streets" — though the term usually refers to unsanctioned art, as opposed to government sponsored initiatives. The term can include traditional graffiti artwork, stencil graffiti, sticker art, wheatpasting and street poster art, video projection, art intervention, guerrilla art, flash mobbing and street installations. Typically, the term street art or the more specific post-graffiti is used to distinguish contemporary public-space artwork from territorial graffiti, vandalism, and corporate art.
About all this sub-styles of Street Art read this article:
Here are some examples of Street Art:
Pseudorealism, also spelled pseudo-realism, is an artistic and a dramatic technique in which an apparently unreal matter is presented in a fashion that makes it appear real. Though use of Pseudorealism has been in practice for sometime in theatre, film, fashion, textiles and literature, as an art genre, it was initiated in Indian art in early 21st century by Devajyoti Ray.
Pseudorealism, or the idea that something unreal can still give the impression of the real has a parallel in mathematical field of representation theory. There a Pseudo real representation is a group representation that is equivalent to its complex conjugate, but that is not a real representation.
Superstroke is a term used for a contemporary art movement with its origins in South Africa. Superstroke is one of the influential art movements regarding African modernism and abstraction. The word "Superstroke" implies the super expressive brush stroke. The Superstroke art movement was initially founded as a reaction to the impact that the Superflat art movement, founded by Takashi Murakami had on modern contemporary art.
Superflat & SoFlo Superflat
Superflat is a postmodern art movement, founded by the artist Takashi Murakami, which is influenced by manga and anime. It is also the name of a 2001 art exhibition, curated by Murakami, that toured West Hollywood, Minneapolis and Seattle.Contents
"Superflat" is used by Murakami to refer to various flattened forms in Japanese graphic art, animation, pop culture and fine arts, as well as the "shallow emptiness of Japanese consumer culture."
SoFlo Superflat describes an art genre started in Miami in the 1990s. It is an urban pop art movement in South Florida that combines super bright colors and ultra flat images. The subject matters are very diverse. It is an outcrop of the Japanese Superflat movement, founded by the artist Takashi Murakami.
Stuckism is an international art movement founded in 1999 by Billy Childish and Charles Thomson to promote figurative painting in opposition to conceptual art. The first group of 13 British artists has since expanded, as of July 2011, to 220 groups in 50 countries.
Installation art describes an artistic genre of three-dimensional works that are often site-specific and designed to transform a viewer's perception of a space. Generally, the term is applied to interior spaces, whereas exterior interventions are often called Land art; however the boundaries between these terms overlap.
Photorealism is the genre of painting based on using the camera and photographs to gather information and then from this information, creating a painting that appears to be very realistic like a photograph. The term is primarily applied to paintings from the United States art movement that began in the late 1960s and early 1970s.
Various modern utilitarian objects have been modified by enthusiasts into a pseudo-Victorian mechanical "steampunk" style. Example objects include computer keyboards and electric guitars. The goal of such redesigns is to employ appropriate materials (such as polished brass, iron, wood, and leather) with design elements and craftsmanship consistent with the Victorian era.