Tax can basically be broken down into different types of taxes:
Corporate Tax is a tax levied on the business entity you choose, such as a C Corporation, S Corporation or LLC. Depending on the entity you choose, there can be a very high corporate tax rate, or none at all. Many states also have a corporate tax.
Individual Tax is the most common tax and generates the most revenue for the government. Individual tax affects your business because you can be taxed on the profits of your business either directly if you pick a "pass through" tax entity like a S Corporation or LLC, or as a dividend if you pick a C Corporation. Paying yourself a salary from your corporation will also be subject to individual tax.
Sales Tax is most often levied on goods in the U.S., but can also be levied on services in other countries, where it is more commonly referred to as VAT. Sales tax can be a tricky subject for e-commerce sellers, but your business usually has to have an economic nexus to the state you are selling in to be subject to sales tax in that state. Sales tax is a state tax and not a federal tax.
Payroll Tax is a tax levied on wages, such as paying yourself a salary from your corporation. It can either be paid one half by your corporation and one half by you if you are an employee, or it can be taken one whole out of your "pass through" profits, as in the case of an LLC. Either way, the federal payroll tax (called "FICA" taxes) will amount to the same percentage, currently around 15% in total (approximately).
State Tax is often a tax on top of the taxes listed above, and can be corporate tax, individual tax, or payroll tax depending on which state you are in. Some states have no personal income tax, while others have an added city corporate tax in addition to the state tax.
For some good general FAQs for tax questions, see the following links: