Reality - that's what they usually report. A good bit more reliably than others as well. The other decent source is C4 also state owned but aiming to be mischievous as they put it themselves.
And sometimes, their 'reality' doesn't quite align with actual reality and that's where Ofcom come in, The BBC has been forced to issue a fair number of apologies over the years, only an idiot would declare them whiter than white.