Transitional markers are words used to link ideas together so that the text is smoother to read. When pronouns such as it, they, them, I, he, she, which, who, whose, that, such, one,and demonstrative adjectives such as this, that, theseand those,are used as transitional markers, they refer to a word, or words, mentioned earlier in the sentence or paragraph. Their function is to take your thoughts back to something that has already been mentioned. Thus they serve as synonyms or substitutes. Other words which are often used to refer backwards are the former, the latter, the first, second, etc., the last.
Now look back at the text 'What Is a Computer?' and find out what the words in boldtypeface refer to.