The followers of Abdul Wahab Najdi are called as Wahhabis.
There are differences at some matters between Deoband and Wahhabis. In order to know the details you should study the book محمد بن عبد الوہاب اور ان کے خلاف پروپیگنڈہ.
Hazrat Maulana Rashid Ahmad Gangohi wrote that he had heard that Abdul Wahhab was a good man, followed Hambali Maslak, but had some strictness in nature.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband