When a company makes the decision to go out of business, it generally cannot simply close its doors the instant it makes that decision. Most businesses have long-term obligations to employees, suppliers and customers as well as landlords and various other parties. A company will have to take time to end these relationships and handle any obligations it has to various stakeholders before it can close its doors.
Once a company has wound up its affairs, it can then sell its remaining assets. Some of these assets, such as remaining inventory, may be liquidated as part of the winding up phase. Others, such as land, buildings and equipment will typically be sold only after the company has completely gone out of business.
Dissolution would be the termination of one's business operations. Dissolution may be the cause of the liquidation. If a business "dissolves" they will in many instances have to liquidate their assets (including office furniture, computers, etc) in order to pay off creditors (or just to get rid of the stuff!).