Here are some basic points to understand about sales tax:

1. Taxable Items: Sales tax is usually applied to a wide range of tangible goods, such as clothing, electronics, and appliances. However, the types of goods and services subject to sales tax can vary by jurisdiction. Some states also tax certain services like dining at a restaurant or staying at a hotel.

2. Tax Rates: The sales tax rate is not uniform across the United States. Each state, and often local jurisdictions within states, can set their own sales tax rates. This means that the rate can vary significantly from one location to another. Sales tax rates are typically expressed as a percentage of the purchase price.

3. Point of Sale: Sales tax is typically collected at the point of sale, which can be a physical store, an online retailer, or other types of transactions. Businesses are responsible for collecting the tax from the customer and keeping track of the amounts collected.

4. Exemptions: Some items may be exempt from sales tax. Common exemptions include groceries, prescription medications, and certain types of clothing. These exemptions can also vary by jurisdiction.

5. Use Tax: In some cases, if a person buys an item without paying sales tax (for example, through an online retailer that doesn't collect sales tax), they may be required to pay a use tax directly to their state's tax authority. This is designed to prevent people from avoiding sales tax by shopping out of state or online.

6. Regulations: Businesses that are required to collect sales tax must comply with specific regulations in their jurisdiction. This includes registering with the tax authority, collecting the appropriate tax amount, and filing regular reports and payments.

It's important to note that the specific rules and regulations surrounding sales tax can vary widely depending on where you are located. It's essential for businesses and consumers to be aware of the sales tax laws in their area to ensure compliance with tax obligations.