A generic satellite receiver (such as a Sky box without a subscription) can receive all of these channels:
https://en.wikipedia.org/wiki/List_of_free-to-air_channels_at_28%C2%B0E
A Freesat receiver actually receives a
subset of those channels in its basic 'out of the box' state
http://www.freesat.co.uk/channels
but the 'missing' channels from my first link can still be received by entering the channel information manually.
So there are actually far more channels available with Freesat than with Freeview
http://www.freeview.co.uk/wp-content/uploads/2015/02/Freeview-Channel-Guide_Feb-2015.pdf
but, since they tend to be specialist channels (as in Woofgang's post), most people probably don't want them anyway.
Further, it's worth noting that some Freeview channels aren't available (without a subscription) via satellite. For example, Dave is only available with a Sky subscription.