What is the difference between qui and que?

Qui and que are both relative pronouns that replace nouns and link two clauses (sentences). For example: La maison est belle and Tuas acheté la maisonYou can combine thesetwo sentences to make one single sentence.1)    La maisonque tu as achetée estbelle.2)    Tu as acheté la maison qui est belle.QUI replaces the subject of the sentence(the thing/person which is doing theaction) and is followed by a verb.It translates to who when referring to a person. It translates to which when referring to things/placesE.g. Le chien qui est là.QUE replaces the object of the sentence (the thing/person that is having something done to it) and is followed by a noun or subject pronoun (Je, tu, il, elle, on, nous, vous, ils, elles).NOTE when it is followed by a word that starts with a vowel it is shortened to qu’.E.g. Le chien que j’ai vu est là.Before you decide whether you are going to use qui or que it is important to determine whether the noun that is being replaced is the subject or object of the sentence.Sometimes it is as easy as simply seeing whether the relative pronoun will be followed by a verb or noun/subject pronoun, however it is not always as obvious as that so it is always important to determine whether the noun is a subject or object.