The first time we meet Hareton Earnshaw is in Chapter Two, when Lockwood decides to take his second ill-advised visit to Wuthering Heights. Let us remember that Hareton is the soon of Hindley Earnshaw and his wife, who dies soon after his birth. He has been left to be brought up by his dissolute and drunken father and then by Heathcliff, who has delighted in treating Hareton in the same way that he was treated by Hindley as a child. Heathcliff has therefore taken away his birthright from him and also deprived him of the education that his position in society demanded, leaving him to grow up to be a rough, uncouth young man. Note how he is described in Chapter Two:
Meanwhile, the young man had slung on to his person a decidedly shabby upper garment, and, erecting himself before the blaze, looked down on me from the corner of his eyes, for all the world as if there were some mortal feud unavenged between us. I began to doubt whether he were a servant or not: his dress and speech were both rude, entirely devoid of the superiority observable in Mr. and Mrs. Heathcliff; hs thick brown curls were rough and uncultivated, his whiskers encroached bearishly over his cheeks, and his hands were embrowned like those of a common labourer: still his bearing was free, amost haughty, and he showed none of a domestic's assiduity in attention on the lady of the house.
So, when we are first introduced to Hareton, just as when Cathy is first introduced to her cousin, his status is rather confusing, as he appears to be a common man but there is something about his bearing and attitude that does not fit this station in life. Of course, as the novel develops, we discover that Hareton's attitude is something that changes, and his love for Cathy is the principal vehicle that is responsible for that change, until, in the final chapter, we are introduced to him as a handsome young man who is quite clearly a gentleman.