"According to", "in accordance with" and "as per" are synonyms for the phrase "according what". These terms are used to indicate that something is being done or said in a manner that is consistent with an established principle or guideline. For instance, if a report is written "according to" the company policy, it means that the report is aligned with the policies and procedures of the organization. Similarly, "in accordance with" is often used to show that something complies with a set of rules, regulations, or standards. "As per", on the other hand, is a more formal way of stating that something is following a specific guideline or instruction. All three phrases are useful in making a statement that is supported by a reference source or authority.