It can be extremely hard to know exactly what you're getting when it comes to oil. Oils are produced in many different ways: some might be extracted using solvents like hexane, and others are expeller pressed with a mechanical press that physically squeezes the oil out.
How oil is produced may not be clearly marked on a retail or bulk label, which makes things even more confusing. Sometimes descriptors about production methods can be found in the title, other times clues are left in an "abbreviated form", or the details may be found only in the description on a spec sheet. To make matters worse, some vendors make no mention at all on how the oil is made on any QA or Marketing documents, so you may just have to know what's "industry standard". This puts it in your hands to ask the right questions and get the proper documentation.
Centra Foods always tries to be as clear as possible. That's why, today, we will explain what the solvent extracting, expeller pressing, and cold pressing methods all look like in detail. When explaining these processes, we will be referring to canola oil specifically because it's one of the oils that is commonly expelled in all three variations. You will notice these processes are going to look very similar for many different type of other seed oils too, so you can apply these general ideas across the board with vegetable oils.