What are Abrams tanks and why is the US sending them to Ukraine?

Canada considering sending 4 Leopard tanks to Ukraine: sources

Ukraine war news: U.S. will send Abrams tanks

U.S. and Germany set to send tanks to Ukraine, breaking deadlock - The Japan Times

What could future deliveries of Western tanks mean for the war in Ukraine?

U.S. poised to approve sending Abrams tanks to Ukraine

US. Will Send Abrams Tanks to Ukraine Ahead of Expected Russian Offensive

Biden admin clears potential $6 billion Abrams tank sale for Poland amid Ukraine situation - Breaking Defense

What is a 'main battle tank,' and how will Ukraine use them? - Breaking Defense

Ukrainian troops to begin training on US-made tanks in next few weeks – POLITICO