Early Childhood is not free to every young children in most states. The US
system mostly covers K-12 (age 5 to 18 and above). To that end, what "early
childhood" (or Preschool) in a public school means here is usually: A,
teaching students from a lower socio-economic bracket, who are more at-risk
to academic failure if early intervention is not provided; B, teaching
students with possible disabilities, like speech difficulty, etc. In my
state, we call them 3Y and 4Y according to the students' ag