Learning to read is the process of acquiring the skills necessary for reading.
That is, the ability to acquire meaning from print. Learning Alphabet is paradoxical in some ways. For an adult who is a fairly good reader, reading seems like a simple, effortless and automatic skill but the process builds on cognitive, linguistic, and social skills developed in the years before reading typically begins.
Writing systems are distinguished from other possible symbolic communication systems in that one must usually understand something of the associated spoken language to comprehend the text. Once established, writing systems on the whole change more slowly than their spoken counterparts, and often preserve features and expressions which are no longer current in the spoken language. The great benefit of writing systems is their ability to maintain a persistent record of information expressed in a language, which can be retrieved independently of the initial act of formulation.
A child’s ability to learn to read, known as reading readiness, begins in infancy, as the child begins attending to the speech signals in their environment and begins producing spoken language. Children make some use of all the material that they are presented with, including every perception, concept and word that they come in contact with; thus the environment in which a child develops affects the child’s ability to learn to read.The amount of time that a child spends together with parents or other important caregivers while listening to them read is a good predictor of the level of reading that the child will attain later in life. As a child sits with a caregiver, looking at pictures and listening to stories, he or she will slowly learn that all the different lines on each page make different symbols and then that together these symbols refer to words. Taking time to read to children is the most important precursor to a child’s development of reading.
Preschool-aged children with limited exposure to books and reading in their home, including limited experience of being read to, are at risk of reading difficulties. For example, these children tend to have less exposure to literary phrases, such as “Once upon a time”, and have smaller vocabularies,both factors that affect the ability to read by limiting comprehension of text. The environment in which a child lives may also impact their ability to acquire reading skills.
More info : https://en.wikipedia.org/wiki/Learning_to_read