A company business structure is a separate legal entity, unlike a sole trader or a partnership structure. This means the company has the same rights as a natural person and can incur debt, sue and be sued.
As a member you’re not liable (in your capacity as a member) for the company’s debts. Your only financial obligation is to pay the company any amount unpaid on your shares if you are called on to do so. However, directors of the company may be held personally liable if found to be in breach of their legal obligations.
Companies are expensive and complicated to set up, and generally suit people who expect their business income to be highly variable, and want the option to use losses to offset future profits.