LinkedIn vs Twitter

LinkedIn is a business-oriented social networking service. 250 million+ members. Manage your professional identity. Build and engage with your professional network. Access knowledge, insights and opportunities.
Twitter is an online social networking and microblogging service that enables users to send and read short 140-character text messages, called "tweets". Registered users can read and post tweets, but unregistered users can only read them.
Face to face in the news:

2012 - What if LinkedIn was invented in the 80s? to catch up with Twitter

If you thought job hunting was difficult today, imagine how painful the process would’ve been in the past, without the Internet.