Surrealism began in the early 1920s after the Dada movement, as avoiding rationalism and enabling artists to combine their unconscious (untapped) with their conscious, hence the term surreal. Things that seems strange or outlandish.
The Lovers by René Magritte, 1928
Some of the greatest artists that were involved in the movement were Andre Breton, Salvador Dali, Frida Kahlo, Rene Magritte, Pablo Picasso (also a Cubist artist, Max Ernst, Giorgio de Chirico, etc.
Philosopher's lamp by René Magritte, 1936
How can one just go about connecting these two parts of their brain, you might think. Well, surrealists used plenty of techniques that allowed them to capture images from moments that bridge them together. Some of those few techniques were collage, automatism, photomontage, games, liquid movements on vertical surface, bulletism, aerography, etc.
Salvador Dali used a nap technique by sitting on a chair and holding a spoon with a plate placed on the floor. After relaxing himself, he would start getting drowsy and then the spoon would slip from his fingers and fall on the plate. At this exact moment he could capture images or scenes that he would be having midway. (the bridge I talked about) This technique helped him to slip into the unconsciousness for a while and get the inspiration he needed which would then be used in his paintings! How strange, isn't it? ;)
Keep Creating
Lots Of Love <3