Explain difference between Ultimate Tag Warrior & Social Networking Pluings

I’m having trouble understanding the diff. bet. a plugin like Ultimate Tag Warrior & the social networking plugins out there. In other words, if you install a social networking plugin do you still have to use something like UTW to send keywords to Technorati for your posts? Or will the social networking plugins do that for you?

I’ve been using UTW for a long time. But I want to install a social networking plugin & want to know if I need to retain UTW.

Also, can folks recommend social networking plugins they like specially?