How preschool can make difference in children's education?

There's a great deal of research evidence showing that children who attend pre-school do better in later years of school. Children learn how to learn, and how to behave in school. Their language skills are built, especially if the teacher employs good strategies when reading to them. Children get very different exposure to language, depending on their parents' level of education and fluency in English. Those children who start kindergarten with better language skills have been shown to do better all the way through school. 

Are you a student in an education course? OR a parent? I'm asking because your question is ungrammatical. It should be "How can preschool make a difference..." If you are a parent, preschool can help your child by exposing him/her to standard academic English.

"preschool" is for those kids whose parent(s) work and thus can not teach their child the fundamental things that all school age children are expected to know.  they are nearly unknown in traditional cultures (where grandmother cares for and teaches the youngest ones).