TIFF and PNG are often discussed together because both can be used in lossless workflows, but their typical purposes are quite different.
TIFF in production workflows
TIFF is common in scanning, publishing, photography and archival workflows because it can support high bit depths, multiple compression methods and rich metadata. Files can be large and are not usually chosen for direct website delivery.
PNG for screen graphics
PNG is simple, widely supported in browsers and well suited to screenshots, interface graphics and images that need transparency. It is easier to use directly on websites but can become inefficient for large photographs.
Editing and interchange
Professional applications often handle TIFF well, while PNG has broader everyday compatibility. The best master format depends on your software, bit-depth requirements and metadata needs.
Conversion considerations
Moving from TIFF to PNG can simplify sharing but may discard TIFF-specific features. Moving from PNG to TIFF does not create additional detail. Keep the original master when those features matter.