What is GIF?
GIF is thirty-eight years old and refuses to die, because it animates and everything opens it. The cost is its palette: 256 colours per frame, so photographs come out visibly banded. Transparency is on-or-off per pixel, with no partial opacity.
What is TIFF?
TIFF is the archival and print format - lossless, high bit depth, and flexible enough to hold multiple pages in one file. Scanners, publishing workflows and document archives lean on it heavily. Browsers have never displayed it, which is why it is offered here as a target rather than a source.