There are like 9 speciality in dentistry like Oral medicine, oral and Maxillofacial surgery, orthodontics, conservative and endodontic, pedodontics, prosthodontics, periodontics, oral pathology and histology and public health dentistry.
And yes endodontist are top tier for your root canal treatment. Though skilled general dentists can do that also.
Oral surgeons on other hand do lots of surgeries like extracting impacted wisdom tooth or canine, aesthetic surgery like rhinoplasty, treat facial fractures, orthognathic surgery and so on.