The "image" of TNG is built upon several distinct design pillars that are instantly recognizable to fans and casual viewers alike:
The visual identity of Star Trek: The Next Generation (TNG) defined a new era of science fiction, shifting from the primary colors and "retro" aesthetic of the 1960s to a sophisticated, warm, and streamlined vision of the 24th century.
Unlike the sharp angles of the original ship, the Enterprise-D features organic, elliptical curves and a massive saucer section. You can find detailed technical specifications and ship imagery at Memory Alpha .