1.) Ahlus-Sunnah wal-Jamaa’ah: This name is from the famous names which Ahlus-Sunnah is known by. It is applied in conjunction with As-Sunnah. So it is said: “Ahlus-Sunnah wal-Jamaa’ah”. And it may come singularly, so that it is said: “Ahlus-Sunnah” and it is said: “Ahlul-Jamaa’ah”; and it (the latter) is used infrequently. That which is more commonly used is coupling it with As-Sunnah. Ibn Taymiyah, may Allaah have mercy upon him, said: “The Sunnah is linked to the unity just as innovation is linked to separation. So it is said: Ahlus-Sunnah wal-Jamaa’ah (the People of the Sunnah and the Jamaa’ah), just as it is said: Ahlul-Bid’ah wal-Firqah (the People of Innovation and Division).” From the reasons for them being called by this name: Ahlus-Sunnah wal-Jamaa’ah, is that they are distinguished by two magnificent characteristics: The First: Their clinging to the Sunnah of Allaah’s Messenger ﷺ to the point that they became its people; as opposed to the rest of the groups. For they cling to their opinions, their desires, and the statements of their leaders. So they are not ascribed to the Sunnah. They are only ascribed to their innovations, their leaders or their actions, as has preceded. The Second: They are the people of the Jamaa’ah due to their unification upon the Truth and their not being disunited. As opposed to the other groups; for they are not united upon truth. They only follow their desires, so no truth unties them. Shaykhul-Islaam said in defining Ahlus-Sunnah: “They cling to the Book of Allaah and the Sunnah of His Messenger ﷺ and that which the first and foremost ones, from the Muhaajiroon, the Ansaar and those who followed them in goodness, agreed upon.”
2.) Ahlul-Hadeeth (the People of Hadeeth): From the names which Ahlus-Sunnah wal-Jamaa’ah are called by is: Ahlul-Hadeeth. This has come frequently in the speech of many of the Imaams; such as Shaykhul-Islaam Ibn Taymiyah and others from the people of knowledge before him and after him. They mention Ahlul-Hadeeth and Ahlus-Sunnah clarifying their beliefs and not differentiating between the two usages. So here we have Imaam As-Saaboonee saying in his (book of) ‘Aqeedah: “Indeed the As-haabul-Hadeeth who cling to the Book and the Sunnah, may Allaah preserve the living from amongst them and have mercy upon their dead, they testify to the Uniqueness of Allaah the Exalted and to the Messengership and Prophethood of the Messenger ﷺ …”, up to the point wherein he said: “Allaah has given refuge to Ahlus-Sunnah (shielding them) from At-Tahreef (distortion), At-Takyeef (questioning the howness of Allaah’s Attributes), and At-Tashbeeh (likening Allaah to His Creation). He has favored them with cognizance and comprehension.” Shaykhul-Islaam Ibn Taymiyah said: “The Madh-hab of the Salaf, Ahlul-Hadeeth was-Sunnah wal-Jamaa’ah…” So that which is intended by (the term) Ahlul-Hadeeth in the books of beliefs of the Salaf, is that they are Ahlus-Sunnah. Ibn Taymiyah said: “We do not mean , by Ahlul-Hadeeth, those who stop short at its traditions, books or narrations. Rather, we mean, by them (Ahlul-Hadeeth) every person who actualizes its preservation, its knowledge and its understanding outwardly and inwardly; and following it outwardly and inwardly. Likewise is Ahlul-Qur’aan.”
3.) Al-Athariyyah or Ahlul-Athar (the People of Narrations): Many of the people of knowledge use this title meaning thereby Ahlus-Sunnah wal-Hadeeth. Ibn Aboo Haatim Ar-Raazee said: “Our Madh-hab and that which we choose as a way is following the Messenger of Allaah ﷺ, his companions and the Taabi’een; clinging to the Madh-hab of Ahlul-Athar such as Aboo Abdullah Ahmad ibn Hanbal.” He said in another place: “The sign of the people of innovations is fighting of Ahlul-Athar. The sign of the heretics (Az-Zanaadiqah) is their calling Ahlus-Sunnah Hashawiyah (the worthless ones). The sign of the Qadariyyah is their calling Ahlul-Athar Mujabbirah (people who believe that man has no free will). The sign of the Murji’ah is their calling Ahlus-Sunnah: ‘Mukhaalifah’ (opposers) and ‘Nuqsaanaiyyah’ (those who fell short). The sign of the Raafidhah is their calling Ahlus-Sunnah: ‘Naasibah’ (those who have enmity for the household of the Prophet, ﷺ)” That has come within the speech of many of the Imaams; such as Aboo Nasr As-Sijzee, Ibn Taymiyah, As-Safaareenee and other than them from the people of knowledge.  They named them with that ascription to Al-Athar (the narrations) and within the legislative usage Al-Athar is a synonym for Al-Hadeeth. The meaning of: Ahlul-Athar, as As-Safaareenee said, is: “Those who only take their Aqeedah from that which has been narrated from Allaah, Majestic is His status, in His book or in the Sunnah of the Prophet ﷺ, or that which is affirmed and is authentically reported from the Salaf As-Saalih from the noble companions and their dignified followers.” This (term) has the meaning of Ahlus-Sunnah, within the application of the Salaf.
4.) Al-Firqah An-Naajiyah (the Saved Sect): Meaning: saved from the fire since the Prophet ﷺ excluded them when he mentioned the groups and said: “All of them in the fire except one.” Meaning (one) is not in the fire.  The Shaykh Al-Haafidh Al-Hakamee said in Ma’aarij Al-Qubool: “The truthful one, the one who is believed (i.e. the Prophet- ﷺ) has informed us that the saved sect are they who are upon the likes of what he and his companions were upon.”
5.) At-Taa’ifah Al-Mansoorah (the Victorious Group): This title is taken from his ﷺ statement within the Hadeeth of Al-Mugeerah ibn Shu’bah, may Allaah be pleased with him: “There will not cease to be a group of my Ummah who are victorious, up until the command of Allaah comes while they are victorious.”
6.) As-Salafiyyah or As-Salafiyoon (the Salafees): This is an ascription to the Salaf. And the Salaf, in the language, is plural for Saalif; and As-Saalif is the one who precedes. As-Salaf Al-Jamaa’ah are those who have preceded. From that is His, the Mighty and Majestic, statement:
فَجَعَلْنَاهُمْ سَلَفًا وَمَثَلًا لِلْآخِرِينَ
“And We made them predecessors and an example for the others” (Az-Zukhroof 43:56)
Al-Baghawee said in explanation of this verse: “The Salaf of are those who have preceded, from the forefathers. So (He is saying): We have made them as predecessors so that the later ones may be exhorted by them (their actions).” Ibn Al-Atheer said: “The Salaf of the person is he who has preceded him by death from his forefathers and relatives. Due to this the first generations from the Tabi’een are called As-Salaf As-Saalih.” This is its usage in the language. As for its legislative usage, then what is intended by As-Salaf As-Saalih? What is their methodology in ‘Aqeedah and what are the most prominent traits of their methodology. This is what we shall come to know, if Allaah wills, within the following lessons.