memes

PNG was built to replace GIF and TIFF.

The Portable Network Graphics (PNG) format was designed to replace the older and simpler GIF format and, to some extent, the much more complex TIFF format.

And it stands to this day, with the exception of animation:

One GIF feature that PNG does not try to reproduce is multiple-image support, especially animations; PNG was and is intended to be a single-image format only.

Though APNG came later, and we even have MP4.

http://www.libpng.org/pub/png/pngintro.html

Bonus:

No detail was too small for consideration in the authors' quest for a near-perfect image format; yea, verily, even the acronym and pronunciation were major topics of discussion. The reason, of course, is the GIF format; some pronounce it with a soft G like giraffe, some with a hard G like gift, and no one really knows what they're talking about. (For the record, the soft G is correct; it is how the author of the format pronounces it.)

"PNG" is always spelled* "PNG" (or "Portable Network Graphics") and always pronounced "ping" in English, not "pinj" or "pee en gee" or any other multi-syllabic disaster. (For non-English speakers, the three-letter pronunciation is fine, however.)