What is the "Mawrood" (frequented) Pond? And what is the difference between it and the River Kawthar?

The Hawd al-Mawrud (the Visited/Frequentable Basin) is a basin on the Plain of Gathering (Yawm al-Mahshar) belonging to the Prophet (peace be upon him). The believers from his Ummah will drink from it. Its length and width are a month's journey. Whoever drinks from it once will never be thirsty again. Its vessels are as numerous as the stars in the sky, and its water comes from Paradise, flowing into it from the River al-Kawthar. Al-Kawthar is a mighty river in Paradise, from which two spouts will pour into this basin on the Day of Resurrection.