I'm just giving an overview. This is not exhaustive.
184 can be divided into 184(1) which talks about General disclosure 184(2) talks about specific disclosure when contract is entered into.
185 is the Prohibitory section. It prohibits providing loan to director and other specified persons. Its worthwhile to note that loan given by the company to director is covered here. Not the loan received by the company.
Whereas 186 talks about Loan given by company to any person. 185 (covers only loan given to director and other specified person) 186 covers all loans given by the company. If a person is not prohibited under 185, then 186 is more of a procedural section.
188 is Related Party Transactions 189 Register of contacts entered into by the Co.
187 says all investments made my company should be held in its own name. (Some exceptions are provided)