A DBA (also known as a "sole proprietorship", "Doing Business As", or a "Fictitious Name") is a business that is not separate from its owner, merely a different name that the business owner operates under. The owner is personally liable for the company and its debt; all income is added on the owners personal tax returns (pass-through taxation). If there is more than 1 owner, than the business is classified as a "Partnership".
PROS: Easy to setup, easy to maintain.
CONS: Owners are personally liable for the company and its debt ( you could lose your house, cars, personal assets, etc.) in a lawsuit. Usually not recognized at the State level, only in your city/county. No corporate "prestige" of having the "Inc." or "LLC" attached to your name.
How to get Started: DBAs are typically filed at the County Clerks office or at the State level. Getting a DBA or FBN can be a complicated task. There are thousands of counties in the United States and each has its own particular filing requirements. Some jurisdictions require a separate publishing in a newspaper that notifies the public of your intent to "do business as" another name.
If you are starting your business as a sole proprietorship or a partnership, then you will need to file a DBA so that you can "do business as" a name other than your real name.
For example: If you are named John Smith and wanted to operate as "JS Enterprises", you would need to file a DBA so that you can a) operate under that name and b) open a company bank account to accept payments made to "JS Enterprises".
If your business is already set up as a corporation or an LLC, and you want to do business under a different name than your existing corporate or LLC name, you will need to file a DBA.
For example: If your company name is ABC Services, LLC and you want to operate as "QuickKleen Services", then you would file a DBA. If you want to operate only as "ABC Services, LLC", then the DBA would not be required.