Similarities: both Spanish, both sought fame and fortune in Paris, both had problems with Franco although Dali less so, both explored painting, sculpture and multimedia, Picasso far more so in the first two, Dali made it or New York and Hollywood. Both lived to be of advanced age, Picasso was healthier, Dali much less so. Both have museums dedicated to their work, both enjoyed wealth during their lives, Picasso more so and both enjoy high auction and sale prices, again Picasso more so. And of course they knew each other, with Picasso stealing more from Dali than vice versa.
Differences: While both are the products of academy training: Picasso eschewed much, although still had a commitment to the figure and realism, Dali never abandoned his love of realism and his classical training, in fact embraced it and rued its decline as distortion and abstraction gained ascendancy. See: Dali on Modern Art for his many funny and passionate remarks. He thought Picasso ridiculous, Picasso didn’t care. Hope this helps ∩^ω^∩
