We’ve learned, from the lessons of our scholars, that differing “اختلاف” is divided into 3 types:
1: Tudaad “التضاد”: Which is to literally clash with the text and is not permissible. 

2: Afhaam “الأفهام”: Which is found in affairs of ijtihaad (independent rulings based on Islamic jurist principles and precepts) found in matters of fiqh and hadith science. This is allowed 

3: Tanawwa “التنوع”: i.e., A variety in how one act of worship can be performed.
Sheikh Ubayd Al Jaabiri said, “O Muslim, who has been led towards guidance and correctness in speech and action, it is incumbent to know that differing between the people of knowledge among the Muslims is from two perspectives:
1: Differing in that which there is neither room for opinion nor an arena for ijtihaad. It is whatsoever pertains to the foundations of the religion (the creed). This type of differing is hated and blameworthy, due to the companions learning such from the Prophet -sallahu alayhi wa sallam. So they were unanimous with regards to this, likewise those who succeeded them from the leaders of knowledge, faith, and religion. No one differed in this except the people of desires along with the differing in their goals.
As a result you know the corruption within the statement, “The companions differed in creed” and I have refuted such in varying passages (and or articles) from them “Warning the intelligent from statements in opposition with the correct.”
2: Differing in rulings that which therein is room for ijtihaad and an arena for opinion. Thus we do not know anyone from the two differing that reprimands the other, as long as all have with them evidence that supports his view. If some from the two parties most likely differs with what another holds (or views) then he must manifest what makes more probable his statement with evidence, without rebuke of who differs with him.”
Statement of the sheikh taken from: إنعام الباري بشرح كتاب الاعتصام من صحيح البخاري