The differences between One and it are: different substitute objects, different parts of speech and different substituted nouns.

1. Different substitute objects

1, one：one When substituting countable nouns of the same kind of people or things, you must add qualifiers, adjectives and possessive pronouns to modify them.

2. it: it can replace gerund phrases, infinitive phrases and clauses in English sentences, and can be used as a formal subject or a formal object in sentences.

second, the parts of speech are different

1, one：one is used as a formal object in the sentence, but not as a formal subject.

2. it: it can be used as a formal subject or a formal object in a sentence.

Third, the substituted nouns are different

1, one：one When replacing the same thing, the substituted nouns can only be countable nouns.

2. it: when it replaces the same thing, the substituted nouns can be countable nouns or uncountable nouns.