The most important thing to remember about limited companies is that each is an individual in Law. Limited Companies are owned by the Shareholders; they are controlled by the Directors; there is no bar to individuals being both shareholders and directors. Directors are usually treated as employees. There are several types of limited companies, those limited by shares, those limited by Guarantee, Personal Service Companies, and Managed Service Companies, etc. Choosing the right one usually requires professional assistance.
Limited Companies pay additional National Insurance Contributions for their employees. Shareholders can be paid dividends, but this process does not reduce the corporation tax payable by the company.