What is Bitbucket ?
Bitbucket is a web-based hosting service that is owned by Atlassian, used for source code and development projects that use either Mercurial (since launch) or Git (since October 2011) revision control systems. Bitbucket offers both commercial plans and free accounts. It offers free accounts with an unlimited number of private repositories.
It is similar to GitHub, which primarily uses Git. Bitbucket has traditionally tailored itself towards helping professional developers with private proprietary code, especially since being acquired by Atlassian in 2010. In September 2016, Bitbucket announced it had reached 5 million developers and 900,000 teams on its platform. Bitbucket has 3 deployment models: Cloud, Bitbucket Server and Data Center.
You can signup free in Bitbucket from its official site http://www.bitbucket.org
After creating Bitbucket account, you can create repositories for your git.