There are lots of flowers we call dandelions and many, of course, are not! They may have yellow dandelion-like flower heads that turn into dandelion-like clocks but they are not dandelions. The challenge is telling them apart. I am not a botanist but by applying some basic principals identification of these tough species (thistles are another one) becomes a bit easier.
Firstly, some species are more common than others and this is a good starting point because you are, statistically, more likely to see a common species than a rare one. Then, time of year and habitat play a role.
This species, autumn hawkbit (Leontodon autumnalis), is common in late summer and throughout the autumn and it can be found in all sorts of habitat but it really loves a bit of rough ground or roadside verge. It has stems that branch out with a single flower on each branch. It is a scruffy, untidy flower that likes scruffy, untidy places. A true 'weed'.