Microsoft officially incorporated as a legal business entity almost exactly 36 years ago today, on June 25, 1981.

At Windows Central, we pride ourselves on not just our knowledge of Windows and its related ecosystem but also the ins and outs Microsoft's history. As such, we like to keep track of notable dates in the company's storied past.

This week contains one of those dates. Thirty-six years ago last Sunday, on June 25, 1981, Microsoft was officially incorporated as a company in the state of Washington. To be clear, Microsoft was founded by Bill Gates and Paul Allen just over six years before that, on April 4, 1975.

What's the difference between being founded and incorporated?

Simple: Founding a company is a casual term for forming it in some capacity. Incorporating is when things get official in the eyes on the law in the United States.

From BizFilings.com:

Incorporating a business means turning your sole proprietorship or general partnership into a company formally recognized by your state of incorporation. When a company incorporates, it becomes its own legal business structure set apart from the individuals who founded the business. Through incorporation, the company's owner or owners create a separate legal entity to transact business. This new business entity corporation or limited liability company (LLC) transforms the way the business is seen through the eyes of the law and often has more credibility with potential customers, vendors and employees.

In other words, by the summer of 1981, Microsoft had reached a point in its growth where its founders and other decision makers decided it was time to get all official in the state of Washington, where it was headquartered in the city of Redmond. (Another tidbit of nerd knowledge: Microsoft was first incorporated in the state of Washington on June 25, 1981, but it reincorporated in Delaware on September 19, 1986, and then reincorporated again in the state of Washington on November 1, 1993.)

June 25 was an important day in Microsoft's history and an early stepping stone on the path toward its evolution into the tech giant it is today.