How will US and German tanks help Ukraine

Both Germany and the US have agreed to send tanks to Ukraine. Berlin will supply its Leopard II and Washington, the M1 Abrams. After resisting for weeks, Germany finally gave in to political pressure. It's also agreed to allow other countries such as Poland and Finland to send Leopard II tanks from their arsenals. They're considered essential for Ukraine, if it's to take back territory captured by Russia early in the war. But will such new weaponry change the course of the conflict?