Here is a brief outline of the domain transfer process for .com, .net, and .org domains. This process is governed by the rules set forth by ICANN
1. The registrant of the domain requests an EPP (transfer) code from the current domain registrar which the current registrar must send.
2. The registrant provides that EPP code to the gaining (new) registrar and initializes the transfer process.
3. The gaining registrar must then get approval from either the registrant or adminstrative contact listed on the domain name.
4. Once the gaining registrar has the approval of the registrant or administrative contact listed on the domain, they then contact the current registrar and request transfer of the domain.
5. The current registrar has 5 days to respond to the transfer process. If, within 5 days, the current registrant does not respond, the transfer will automatically complete.
For a full description of all the rules and processes governing .com, .net, and .org domains, please see ICANN's website at: http://icann.org/en/transfers/policy-en.htm