Artist has 24 physical I/O ports available - Elements has 24.
Artist has up to 64 audio, 128 MIDI and 32 instrument tracks - Elements has 48 audio, 64 MIDI and 24 instrument tracks.
Artist has more VSTi’s slots than Elements.
Artist has MixConsole History, Elements doesn’t.
Artist has full-screen mode, Elements doesn’t.
Artist has sidechaining, Elements doesn’t.
Artist has 32 Group Channels, Elements has half that.
Artist Key and Drum editors and Chord Pads are enhanced in Artist - basic in Elements.
Artist has Track Versions and Full Instrument Expression control - Elements doesn’t.
Artist has more VSTi’s and Plug-ins than Elements.
Artist has full audio editing toolset, Elements only has basic.
Artist has Realtime time-stretching and pitch-shifting including zplane Elastique v3 algorithms - Elements can only do this for playback.
Artist supports Lanes and Comping and dedicated punch points - Elements has none of these.
Artist has Track Visibilities, Render-in-place and VST Transit - Elements doesn’t.
Apart from that, they are the same.