The word graffiti comes from the Greek word graphein, which means to write. Modern graffiti was born in the 1960s in New York  and was inspired by hip-hop music. The number of graffiti signatures an artist has depends on the reputation and fame of the artist.
Although sometimes this type of art has remained under the radar, and despite the fact that authorities have spent lots of money in erasing graffiti, street art has spread to other countries and has become popular in urban spaces in many cities. Some are scrawls with personal messages, and others are true works of art. In this time of economic crisis graffiti art is rife with social demands, and like it or not, has become part of our daily life.
Many webpages dedicate their content to showcase this type of street art such as the blog Fogonazos , a collection of which can be seen here:
These photographs below (taken by the author) show the wave of graffiti that can be seen while walking through Granada, in southern Spain, the compelling images and phrases making reference to the political and economic system of the country.
In the third photograph, one can see the letters PP (the Spanish Popular Party) and PSOE (the Spanish Socialist Workers’ Party). The abbreviations of the two most popular political parties in Spain appear to be muddled with a single logo: a way of saying that the two parties are the same, which denounces the two-party system. One can also see a mural in the city with chickens with the caption “Gente presa, mercado libre” (People become prey in a free market).
In Madrid you can often find graffiti by the well known Basque artist Alberto Basterrechea , who started writing poetry more than seven years ago. He is the author of two blogs titled Neorrabioso  and Batania  in which he presents photographs of his verses plastered on the walls of the capital city. His poems tend to have a personal edge or often have a demanding tone to them, as we can see in the following photographs:
In any part of the world , it is common for pedestrians to walk amongst all types of paintings on the exterior walls of buildings, parks and houses. But beyond the city walls, graffiti has moved from the streets to other types of media: photography books, blogs and Facebook pages such as Global Street Art .