First sight words is a common term in reading that has a variety of meanings. When it is applied to early reading instruction, it typically refers to the set of about 100 words that keeps reappearing on almost any page of text.
In addition to their being very frequent, many of these words cannot be “sounded out.” Children are expected to learn them by sight (that is, by looking at them and recognizing them, without any attempt to sound them out.)

First Sight Words groups 300 sight words into different levels. It contains both table model and flash cards model.
Word pronunciation is played on tapping the word in both models.

First Sight Words are the most common words in English and are the most important words in learning to read:
The first 7 levels contains 100 words which make up about 50% of the words in reading.
The total 300 words make up around 70% of the words used in reading.