It is said that erotica is brunettes in silk and pornography is blondes in nylon. Erotica is for nice middle class literate people and pornography is for the lonely, unattractive and uneducated.
Porn videos aims at arousing sexual instinct in people and help to stimulate but erotic content may not have such impact.
Here are the differences between the two:
Erotica: Erotic content means any form of art or literature that is erotic in nature. That is erotic content presented in artistic ways for intensions other than just sexual arousal is erotica. This content may increase sexual excitement. It may or may not include nudity but does not have any kind of sex. It can be anything like painting, sculpture, photography, drama, music, cinema and literature.
The erotic movie is designed to sexually arouse but also to stir other emotions like joy, sorrow and anger in the viewer. There is a compelling story, a message, and well-developed characters in erotic films. The well-crafted sex scenes are integral to the story and do not necessarily arouse the audience; it is a movie that portrays sex contextually and has artistic merit.
Porn: This is the just opposite of erotica. The one and only aim of porn videos is to arouse sexual feelings in the viewer. Pornography has nothing to do with art or aesthetics. Its purpose is to stimulate sexual feeling in human. It includes nudity and sexual act.
But the typical pornographic movie intends to sexually arouse a male audience. The film does not contain a gripping narrative or message. The women are often young and have very similar looks (i.e., big breasts, small frame, blonde hair). The female characters are hypersexual objects who seem happy to be at the disposal of men. This type of movie tends to mix explicit sexual images, submission, and violence, and targets this violence towards women.