I’ll try to confine to your question/description:
- it’s lossless
– it supports layers
– it’s widely used on for publishing purposes
– it has various compression options
– it supports (at least) rgb and cmyk colour models and colour management
– it’s not pattented (although it’s owned by Adobe)
– it’s good for raster or vector data
– it supports 1, 2, 4, 8, 16, 24, 32 bit color depth
– it also supports indexed color
– it supports transparency
– it supports multi-pages
In conclusion, it’s a great choice if you need to need to send some work printing, but it’s definitely not a good choice for web sites: as far as I know, browsers don’t support it, and the files will very likely be huge. It could also be a good choice for archiving content.