Pinterest is popular website featuring information in the form of blocks with images and text. Each block of information is called a Pin by Pinterest. Each pin displays some information posted by its users. Many other websites around the world followed its style of displaying pins like boxes to post information.
You can follow a Pin, Save a Pin and the website automatically considers your new tastes or interests and starts displaying relevant or related pins. This process seems to be endless as one feels even after traversing through many pins. Unlike Youtube, Pinterest has no option to mark a pin as inappropriate. Explicit content appears on some pins all of a sudden which belongs to one of your interests you marked when you first signed up for Pinterest or added to your list by browsing Interests list.
You can opt out of certain interests if those pins show explicit content. Click on Account Icon on top right after logging in. Now click on following option. This reveals all followed categories. Simply choose follow or unfollow.