A handy way of filtering some sources before looking at them is to look at the website address. All websites have an address, which you can see in the address bar of the browser.
Originally intended for use by for-profit business entities e.g. www.amazon.com
Originally intended for use by non-profit organizations e.g http://www.cushmanschool.org/
Originally intended for use by organizations involved in networking technologies, such as Internet service providers and other infrastructure companies e.g. https://www.speedtest.net/
Limited to United States federal, state, country and local government bodies e.g. https://www.whitehouse.gov/
Almost entirely used by US universities and colleges e.g https://www.harvard.edu/
Credit: https://www.etbi.ie/