Sole proprietorships are taxed on the individual owner's personal income tax return, partnerships are pass-through entities where profits and losses flow through to the partners' personal tax returns, while corporations are taxed as separate legal entities and pay taxes on their profits at the corporate tax rate.

Sole proprietorships and partnerships are considered pass-through entities for tax purposes, meaning that the business itself does not pay taxes on its profits but rather the profits are "passed through" to the owners' personal tax returns and they are taxed at the individual income tax rate. This allows for a simpler tax process for small businesses as they do not have to file separate tax returns for the business.

Corporations, on the other hand, are taxed as separate legal entities and pay taxes on their profits at the corporate tax rate, which is typically lower than individual income tax rates for higher income brackets. This means that corporations are subject to double taxation, as the profits are taxed at the corporate level and then again when distributed to shareholders as dividends.

Overall, the choice of business structure can have significant tax implications and it is important for business owners to consider the tax consequences when deciding on the most appropriate structure for their business. Consulting with a tax professional or accountant can help ensure that the business is set up in a way that minimizes tax liabilities and maximizes tax advantages.