Structural, presentational and behavioral are the three layers or aspects of web designing. Structural = HTML, presentational = CSS, behavioral = DOM and scripting. Wondering why Iâm talking about web designing here? Well, the tattoo pictured above is all about web designing. The three little tats represent the three layers of web designing. Iâve witnessed innumerable amazing tats but never thought someone would ever come up with such a cool tat! This tat is adorned by Lynn, a Front End Developer, done recently over at Momâs Body Shop in San Francisco.