What's the DREAM Act?
The DREAM Act, which stands for Development, Relief and Education for Minors, is a bill that would provide for conditional legal permanent residency to certain undocumented young adults. In a nutshell, the bill establishes that people might be eligible for permanent residency if they have lived in the U.S. for at least 5 years before the bill is enacted, and the applicant is a high school grad with good moral character (there are a few other requirements, but that's the basics of it).
The DREAM Act was initially introduced in 2001, and was most recently reintroduced in 2011.
If you have any questions on the DREAM Act or deferred action, you should speak with an immigration lawyer.