It can be broad but this usually means practice management and treatment planning. Like some dentist let there assistance do things that other dentist do not, like using an EDA to restore a prep in states where this is legal. Also some dentist will do huge amalgam/composite restorations (3+surfaces) where others treatment plan for a full coverage crown on anything bigger than a class 2. There are also dentists that believe in doing mass occlusal adjust/eq where others dont believe in this. As you can see practice philosophy is a broad subject. Most dentists practice based on who mentored them and CE they have taken, there is no wrong philosophy to practice buy as long as you are not hurting people.