Obama’s Twitter name for the last several years has been @POTUS. As the White House transitioned from Obama to Trump, the Twitter account was part of the transition.
All tweets from Obama’s presidency are archived under a new Twitter name @POTUS44. Twitter automatically switches all the 13 million followers of the Obama-presidency @POTUS to follow @POTUS44 and the @POTUS account for Trump.
CEO Jack Dorsey explained why.