I would want to know the differences between the Sunni Muslims and the Salafi Muslims?

All praise be to Allah and may His peace and blessings be on His final and greatest messenger, Muhammad.
Dear Enquirer,
The word Sunni means one who follows the Sunnah, which means the path of the messenger of Allah (Allah's peace and blessings be upon him).
The word Salafi means one who follows the Salaf, which are the righteous predecessors, namely the scholars and Muslim imams from the first three generations.
Following the first three generations, more particularly that of the Sahabah, is the path recommended by the messenger of Allah. He (Allah's peace and blessings be upon him) said:
عن عبد اللَّهِ بن عَمْرٍو قال: قال رسول اللَّهِ : “لَيَأْتِيَنَّ على أُمَّتِي ما أتى على بَنِي إِسْرَائِيلَ حَذْوَ النَّعْلِ بِالنَّعْلِ، حتى إن كان منهم من أتى أُمَّهُ عَلَانِيَةً لَكَانَ في أُمَّتِي من يَصْنَعُ ذلك وَإِنَّ بَنِي إِسْرَائِيلَ تَفَرَّقَتْ على ثِنْتَيْنِ وَسَبْعِينَ مِلَّةً وَتَفْتَرِقُ أُمَّتِي على ثَلَاثٍ وَسَبْعِينَ مِلَّةً كلهم في النَّارِ إلا مِلَّةً وَاحِدَةً قالوا وَمَنْ هِيَ يا رَسُولَ اللَّهِ قال ما أنا عليه وَأَصْحَابِي.” قال أبو عِيسَى هذا حَدِيثٌ مُفَسَّرٌ غريب لَا نَعْرِفُهُ مِثْلَ هذا إلا من هذا الْوَجْهِ ‏‏‏.‏ وفي رواية قال “هي الجماعة، يد الله على الجماعة‏”.‏
“My nation will experience everything that the Children of Israel had experienced, following in their footsteps exactly, so much so that if one of them had approached his mother publicly for sex, one of my nation will do the same. The Children of Israel divided into 72 sects. My nation will divide into 73 sects, and all of them will be in the Hellfire save one.” The people asked him: “And which one will that be? He replied: “The one that follows what I and my Companions are upon right now.” And in a different narration, he said about that group: “It is the group/mainstream; Allah’s hand is with the group.”
This hadeeth has been authentically reported – though some disagreed with its authenticity – by Ahmad and the books called as-Sunan, including at-Tirmidhi from which is the above mentioned wording. Its meaning has its roots in the Quran, Allah said:
“فَإِنْ آمَنُواْ بِمِثْلِ مَا آمَنتُم بِهِ فَقَدِ اهْتَدَواْ وَّإِن تَوَلَّوْاْ فَإِنَّمَا هُمْ فِي شِقَاقٍ فَسَيَكْفِيكَهُمُ اللّهُ وَهُوَ السَّمِيعُ الْعَلِيمُ.”
“So if they believe as ye believe, they are indeed on the right path; but if they turn back, it is they who are in schism; but Allah will suffice thee as against them, and He is the All-Hearing, the All-Knowing.” [Al-Baqarah:137]
The people addressed by this are none but the Sahabah (may Allah be pleased with them).
Given the above, as well as Allah’s accreditation of the Sahabah in many verses of the Quran, it is obvious that the two words Sunni and Salafi overlap, despite having different linguistic origins. It is an overlap like that of Iman and Islam…etc.
It is important, however, to observe that the claim does not necessarily always match the reality. One may claim to be Sunni or Salafi without living up to such noble claims.
The following are signs of those who are both Sunni and Salafi (in truth):
• They follow the revelation (Quran and Sunnah) and quote it appropriately. And they are keen to seek out the authentic Sunnah of our most beloved, Prophet Muhammad (peace be upon him).
• They understand the revelation according to the understanding of the righteous predecessors, which are the companions, and those who followed in their footsteps. They don’t reject or defy the consensus of the previous generations.
• In matters of Aqeedah, they receive their faith from the pure sources of the Quran and Sunnah. They don’t liken Allah to his creatures, nor do they negate his attributes. They believe Allah’s rule (Shari’ah) is supreme, and work for its implementation in their societies.
• They believe in predestination without negating man’s choice…etc.
• In matters of fiqh, they may – or may not – follow a madhhab, but are always keen to abide by the Sunnah when it is clear.
• They don’t pursue illegitimate concessions, nor do they neglect to enjoy legitimate ones. They follow a path of moderation between extremism and laxity. And most importantly, they do what they say and vice versa.
• They avoid innovations and resist any addition to or deletion from the deen. A true Salafi is one who says about the companions the opposite of what the disbelievers said! The disbelievers said:
“وَقَالَ الَّذِينَ كَفَرُوا لِلَّذِينَ آمَنُوا لَوْ كَانَ خَيْرًا مَّا سَبَقُونَا إِلَيْهِ وَإِذْ لَمْ يَهْتَدُوا بِهِ فَسَيَقُولُونَ هَذَا إِفْكٌ قَدِيمٌ.”
“The Unbelievers say of those who believe: “If it were a good thing, (such men) would not have gone to it first, before us!” And seeing that they guide not themselves thereby, they will say, “this is an (old,) falsehood!” [Al-Ahqaf-46/11] Again, those who believed during the time of this revelation are none but the Sahabah. It is our duty to say: “”If it were a good thing, (such men) would have gone to it first.”
• In matters of the history of Islam and the companions and the great imams, they speak well of them and abstain from any mention of them that is belittling or defaming. They respect the scholars of Islam, particularly the ones whose leadership is agreed upon, such as the four imams, Abu Haneefah, Malik, ash-Shafe’ee and Ahmad. And they do so without giving any of them the position of the Messenger of Allah, who is obeyed without questioning in all matters. They are moderate in their following of the madhahib between the extremes of excessive zeal and contempt.
• They work for unity amongst the Muslims. They love them and fear for the disobedient and misguided amongst them and seek to help them through advice (naseehah). They care about the Muslims and grieve over the afflictions the nation may encounter. And they have allegiance for the believers regardless of their race, color, language, nationality, tribe or social or economic status. They never aid their enemies against them.
Having said all that, I prefer that the name Salafi is not used as a way of creating dissension or division, or as a symbol of status, but rather, it may be used at times when one wants to assert his/her following of the early generations.
Allah knows best.