I've been thinking about the Sorcerer and how I feel about them compared to Wizards, so I'll give this a go.
Overall, they're very similar to Wizards. I'd say that the differences between Wizard and Sorcerer are no larger than the differences between subclasses in some other classes. So, starting from the Wizard (which you can see in the
Basic Rules):
Sorcerers have a smaller spell list. They generally keep all of the Wizard combat spells (and many others), but the Sorcerer spell list takes ~2.5 columns while the Wizard spell list is over 4 columns. That's not small -- the Cleric spell list is shorter than the Sorcerer's -- it's just that the Wizard spell list is huge.
Sorcerers have sorcery points, which can be used for metamagic or turned into extra spell slots. The extra spell slots you can get from them are roughly equivalent to the Wizard's Arcane Recovery feature, so no big difference there. You can also shuffle around your spell slots by converting them to/from sorcery points, but the exchange rates are bad enough that you generally won't want to.
Metamagic has some nice effects. Overall, I'd say the main benefit is action economy -- you can pack more into each spell but cast fewer spells total (since you're using sorcery points for metamagic instead of spell slots). You can't get any effects as strong as, say, casting two fireballs per round, but you can get a bit of extra oomph (duration, damage, range, etc.).
Finally, you get to choose a bloodline: draconic or wild magic. Dragon Sorcerers make good combat casters. They get extra AC, hit points, and damage with a specific element. Overall, I'd say they're strong competition for evocation Wizards. Tougher and somewhat more damage, but you lose out on Sculpt Spells, which is huge.
Wild magic Sorcerers have a couple minor luck-affecting abilities, but mostly the point seems to be the wild magic surge table. There's lots of fun stuff in there, but it only ever happens when the DM asks for it.