Calibri is a humanist sans-serif typeface family designed by Lucas de Groot in 2004 and reached the general public on January 30, 2007, with the release of Microsoft Office 2007 and Windows Vista on that date. In Microsoft Office 2007.
Calibiri replaced Times New Roman as the default typeface in Word and replaced Arial as the default in PowerPoint, Excel, Outlook, and WordPad.
It continues to be the default in Microsoft Office 2010, 2013 and 2016, and it is now the default font in Office for Mac 2016. A subtly rounded design, de Groot described it as having "a warm and soft character". -Wikipedia