Shaykh Abdus Salaam As-Suhaymee, said, “Let us begin briefly defining the titles of Ahlu Sunnah Wal Jamaah:
1. Ahlu Sunnah Wal Jamaah (The People Of The Sunnah And The United Group (Upon The Truth))
This name is from the famous names which Ahlu Sunnah is known by. It is applied in conjunction with As-Sunnah. So it is said: “Ahlu Sunnah Wal Jamaah”. And it may come singularly, so that it is said: “Ahlu Sunnah” and it is said: “Ahlu Jama’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: AHLU SUNNAH WAL JAMAAH (The People Of The Sunnah And The Jamaah), just as it is said: Ahlul Bidah Wal Firqah (The People Of Innovation And Division).”[ Al-Istiqaamah 1/42]
From the reasons for them being called by this name: Ahlu Sunnah Wal Jamaah, is that they are distinguished by two magnificent characteristics:
The First: Their clinging to the Sunnah of Allaah’s Messenger (sallAllahu ‘alayhi wa sallam) 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 Jamaah 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 Ahlu Sunnah, “They cling to the Book of Allaah and the Sunnah of His Messenger (sallAllahu ‘alayhi wa sallam) and that which the first and foremost ones, from the Muhaajiroon, the Ansaar and those who followed them in goodness, agreed upon.”
(Imam Al-Asbahaanee (d.535H) said in Al-Hujjah fee Bayaanil Mahajjah 1/364, “The sign of AHLU SUNNAH is that they follow the Salaf us-Saalih (righteous predecessors) and abandon all that is innovated and newly introduced into the Deen.”
Imam Ahmed (d.241H) said in Tabaqaat ul-Hanaabilah 1/184, “The graves of AHLU SUNNAH from those who committed the major sins are like gardens. And the graves of Ahlu Bidah from amongst their most pious ones are hollow and empty. The sinners of AHLU SUNNAH are the Awliyaa (friends) of Allaah and the most pious ones of Ahlu Bidah are the enemies of Allaah.”)
2. Ahlu Hadeeth (The People Of Hadeeth)
From the names which Ahlu Sunnah Wal Jamaah are called by is: Ahlu 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 Ahlu Hadeeth and Ahlu 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 ASHAABUL HADEETH (The People Of Hadeeth) 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 (sallAllahu ‘alayhi wa sallam)…”
And he said, “Allaah has given refuge to AHLU 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 Madhab of the Salaf, AHLU HADEETH WAS-SUNNAH WAL JAMAAH (The People Of Hadeeth And The United Group Upon The Sunnah)…”
So that which is intended by (the term) Ahlu Hadeeth in the books of beliefs of the Salaf, is that they are Ahlu Sunnah.
Ibn Taymiyah said, “We do not mean, by AHLU HADEETH, those who stop short at its traditions, books or narrations.
Rather, we mean, by them (Ahlu Hadeeth) every person who actualizes its preservation, its knowledge and its understanding outwardly and inwardly; and following it outwardly and inwardly. Likewise is Ahlu Qur’aan.”
3. Al-Athariyyah or Ahlu Athar (The People Of Narrations)
Many of the people of knowledge use this title meaning thereby Ahlu Sunnah Wal Hadeeth (The People Of The Sunnah And Hadeeth).
Ibn Aboo Haatim Ar-Raazee said, “Our madhab and that which we choose as a way is following the Messenger of Allaah (sallAllahu ‘alayhi wa sallam), his companions and the taabi’een (the companions students and their students, students); clinging to the madhab of AHLU ATHAR such as (Imam) Aboo Abdullah Ahmad Ibn Hanbal.”
He said in another place, “The sign of the people of innovations is fighting of Ahlu Athar.
The sign of the heretics (Az-Zanaadiqah) is their calling Ahlu Sunnah, Hashawiyah (the worthless ones).
The sign of the Qadariyyah is their calling AHLU ATHAR, Mujabbirah (people who believe that man has no free will).
The sign of the Murji’ah is their calling AHLU SUNNAH, Mukhaalifah (opposers) and Nuqsaanaiyyah (those who fell short).
The sign of the Raafidhah is their calling AHLU SUNNAH: ‘Naasibah’ (those who have enmity for the household of the Prophet (sallAllahu ‘alayhi wa sallam).”
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: Ahlu Athar, as As-Safaareenee said, is, “Those who only take their aqeedah (Islamic beliefs) from that which has been narrated from Allaah, Majestic is His status, in His book or in the Sunnah of the Prophet (sallAllahu ‘alayhi wa sallam), or that which is affirmed and is authentically reported from the Salaf As-Saalih (rigtheous predecessors) from the noble companions and their dignified followers.”
This (term) has the meaning of Ahlu Sunnah, within the application of the Salaf.
4. Al-Firqah An-Naajiyah (The Saved Sect)
Meaning: saved from the fire since the Prophet (sallAllahu ‘alayhi wa sallam) 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 sallAllahu ‘alayhi wa sallam) has informed us that the SAVED SECT (Al-Firqah An-Naajiyah) 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 (sallAllahu ‘alayhi wa sallam) 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-Salafiyyoon (As-Salafiyyeen/The Salafis)
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-Jamaah are those who have preceded.
From that is His, the Mighty and Majestic, statement, “And We made them predecessors (salaf) 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.”
(Imam Adh-Dhahabee (d.748H) said in Siyar 16/457, “It is authentically related from Ad-Daaraqutnee that he said: ‘There is nothing more despised by me than ‘ilmul-kalaam (innovated speech and rhetorics).’ I say: He (Imam Ad-Daaraqutnee) never entered into ilmul-kalaam, nor argumentation. Rather, was a SALAFI (a follower of the Salaf us-Saalih).”
Imam As-Sam’aanee (d.562H) said in al-lnsaab (3/273): “AS-SALAFI: this is an ascription to the Salaf and following their ways, in that which is related from them.”
lbn al-Atheer (d.630H) said in al-Lubaab fee Tahdheebul-lnsaab (2/162), commenting upon the previous saying of as-Sam’aanee: “And a group were known by this ascription.”
(So the meaning is: that the term SALAFI, and its ascription to them, was a matter known in the time of Imam as-Sam’aanee, or before him.))
This is its usage in the language…
(My (Abdul Kareem Ibn Ozzies words) – Sunni is another word for Ahlu Sunnah Wal Jamaah when used correctly and carries a similar meaning to SalafI, but Shaykh Abdus Salaam as-Suhaymee didn’t include it in his book for some reason and Allah knows best why he didn’t include it in his book.
Sa’eed Bin Jubair said, “That my son accompanies a sinful and cunning scoundrel who is a SUNNI is more beloved to me than that he accompanies a devoteful (innovator) and innovator who worships (Allah) regularly.” Ref: Al-Ibaanah no. 89
Shaykh Saalih As-Suhaymee said, “…The SUNNI O you Miskeen (impoverished person) is the SALAFI, and the SALAFI is the SUNNI.
Whoever distinguishes between the two then he has distinguished between two things which resemble each other; so the Salaf are the AHLU SUNNAH and the SALAFIYYOON are the followers of the Sunnah, and whoever absolves himself from that then he is not a SUNNI nor a SALAFI!
…AHLU SUNNAH, THE SALAF, THE FOLLOWERS OF THE SALAF (i.e. Salafis), THE FIRQAT AN-NAJJEEYAH (The Saved Sect), THE TAIFAT UL-MANSOORAH (The Victorious Group), THE JAMAAH (the (United) Group is a short way of saying Ahlus Sunnah Wal Jamaah), THE SALAFI and THE SUNNI, all of these mean one title.
They are the Jamaah (the orginal Islamic United Group (Upon The Truth) and are not a misguieded sect)…” Ref: Shaykh’s lesson from the Explanation of An-Nasihah al-Waladeeyah li Abee al-Waleed al-Bajee (Rahimullaah), end of tape one
Also Shaykh Ubayd Al-Jabiree said, “Both of these terms (SUNNI and SALAFI) carry one and the same meaning (when Sunni is used with the correct meaning) as they are the reference to the same thing.
These are the two terms for any individual whose actions are in accordance to the sunnah of the messenger of Allah and the salaf of this ummah, of the pious predecessors (Salaf us-Saalih), the earlier generations of this ummah…” Ref: http://playit.pk/watch?v=k8AV_FIGPag
Plus Shaykh Mohammed Bazmool said, “…Every SALAFI is a SUNNI and every SUNNI is a SALAFI most definitely, if we are using the word “SUNNI” with its CORRECT MEANING (not the incorect meaning used commonly today: SUNNI (incorrectly) meaning any Muslim who doesnt belong to a Shia sect whether SALAFI or not)…SALAFIYYAH and SUNNIYYAH are the same thing, and thats (why) every SALAFI is a SUNNI and every SUNNI is a SALAFI…” Ref: Bakkah.net)
Ref: Be Salafi Upon the Path By Shaykh Abdus Salaam As-Suhaymee
 Al-Istiqaamah 1/42
 Majmoo’ Al-Fataawaa 2/375
 Aqeedah As-Salaf As-haabil-Hadeeth pg. 423
 Dara’ Ta’aarudh Al-‘Aql wan-Naql 1/203
 Majmoo’ Al-Fataawaa 4/95
 Sharh Usool I’tiqaad Ahlus-Sunnah wal-Jamaa’ah 1/179
 Sharh Usool I’tiqaad Ahlus-Sunnah wal-Jamaa’ah 1/179
 See: Wasitiyah Ahlus-Sunnah Bayna Al-Firaq pg. 119
 Lawaami’ Al-Anwaar 1/64
 See: Wasitiyyah Ahlus-Sunnah Bayna Al-Firaq pg. 119
 This is derived from his (sallAllahu ‘alayhi wa sallam) statement: “Indeed my nation will be divided into 73 groups; all of them in the fire except one. And it is the Jamaa’ah.” And in another narration: “That which I and my companions are upon.”
 He has erred who differentiates between the victorious group and the saved sect. For they are the same thing.
Posted by Abdul Kareem Ibn Ozzie