Muslims belong to the Sunni sect are spread across the globe and make up for 90 percent of the Muslim population, whereas the members of the Wahabi sect are concentrated in Saudi Arab, though a small percentage of them is located in other parts of the world as well.
Sunni Muslims follow Prophet Muhammad and his close companions, whereas Wahabi Muslims follow Muhammad ibne Abdul Wahab, who was present in Saudi Arabia in the 18th century. Muhammad ibne Abdul Wahab was a proper Muslim and consequently follower of Prophet Muhammad himself, but his views on religion and the following the teachings of Quran were far more rigid, which made him come off as a bit of an extremist in the eyes of some Muslims.
Another really major difference between Sunni and Wahabi Muslims is their standing on the four schools of thoughts of fiqah, more commonly known as the Islamic laws. While the Sunni Muslims belief in the four imams, namely imam Hanfi, imam Hanbli, imam Malakii and imam Shaafeyii, the Wahabi Muslims do not follow any of the aforementioned imams. Instead, they strictly adhere to the teachings and laws that are clearly mentioned in the Quran.
Sunni Muslims are generally perceived as moderate, who believe in the equality of women and treat members of other sects with a lot of respect. Wahabis, on the other hand, are believed to be fundamentalists who follow a very orthodox version of Islam. They are said to be intolerant towards other sects such as Shias and are very strict in social and cultural matters, especially the treatment of women. It is believed that they do not allow their women to work alongside men and also do not allow them to even drive a car.
Sunni Muslims believe that Prophet Muhammad is still present in this world despite his death and often address him while praying to God, i.e. Allah, whereas Wahabi believe that the soul of Prophet Muhammad has departed from this world and should not be used as an intermediary while praying to God. They strongly object to the use of pious individuals, either dead or alive, as middle-men while asking God for something.
Sunni Muslims believe in mysticism and intercession, whereas Wahabi Muslims do not believe in such things. Similarly, Wahabi Muslims are against the practice of visiting the tombs and shrines of saints.
Wahabi Muslims differ from Sunni Muslims on the matter of celebrating the birthday of Prophet Muhammad. The former are against this practice and liken it to the ways of infidel Hindus, where the latter celebrate it every year with religious vigour.