How was Nixon's Vietnamization different from Johnson's Americanization of the war?

Use of ground troops: Americanization used US ground troops to fight the war whereas Vietnamization used S. Vietnamese ground troops to fight the war.

Johnson moved the US from an aid and financial backer to a ground force with men in active duty on the front lines in addition to naval and air support. Nixon's policy removed the ground troops, leaving the S. Vietnamese to fight that on their own (with our aid and money) but continued our air strikes and naval support.