Hafiz Ibn Hajar rahimahullah explains what is Shia, Rafidi, & Extreme Rafidi

 

Ḥāfiẓ Ibn Ḥajar ‘Asqalānī rahimahullah writes in Hadiyy as-Sārī p.459, 

‘Shī’iyyat is love for Sayyidunā ‘Alī radiyallahu 'anhu and taking him to be more virtuous than the rest of the Ṣaḥābah radiyallahu 'anhum. So, the person who takes Sayyidunā ‘Alī radiyallahu 'anhu to be more worthy of Khilāfat than Sayyidunā Abū Bakr radiyallahu 'anhu and Sayyidunā ‘Umar radiyallahu 'anhu, he has exceeded the limits in Shī’iyyat. Such a person is called a Rāfiḍī, he is not called a Shi’ī.

 
Then, together with giving preference to Sayyidunā ‘Alī radiyallahu 'anhu in the matter of Khilāfat, he swears Shaykhayn and others, and shows his hatred for them, he becomes an extreme Rāfiḍī. If he believes in the return of Sayyidunā ‘Alī radiyallahu 'anhu to the world (the belief of Raj'at, then it is something even worse than extremism in Rāfiḍiyyat.’

[The scholars must also be aware that narrators like Jabir Ju'fi and Abu Mikhnaf - Lut bin Yahya have fabricated lies and stories about the Sahabah radiyallahu 'anhum. These lies can never be accepted by any Muslim, even if they are mentioned in the works of history. We absolve ourselves from those who perpetuate the lies about the Sahabah radiyallahu 'anhum and the Ahl-ul-Bayt radiyallahu 'anhum.] 

Note: The Shia in general today swear the Sahabah radiyallahu 'anhum after every prayer. Hence, they are extreme Rafidis. They are not Muslims. One cannot befriend them, marry amongst them, eat of their slaughtered animals, pray for them, or unite with them. 

May Allah Ta'ala bless us with understanding and save the Ummah from the evil of the Shia, and the evil of those who call for unity and love for them. Ameen