Phonics is simply the system of relationships between letters and sounds in a language. When your kindergartener learns that the letter B has the sound of /b/ and your second-grader learns that “tion” sounds like /shun/, they are learning phonics.
Learning phonics will help your children learn to read and spell. Written language can be compared to a code, so knowing the sounds of letters and letter combinations will help your child decode words as he reads. Knowing phonics will also help your child know which letters to use as he writes words.