That form is issued by Banks, Credit Unions or investments accounts (Brokers/Mutual Funds)....reporting that you received interest income, usually from:
1) Bank accounts or taxable bond interest in box 1 of the form.
2) US Savings bonds or US Treasury in box 3 of the form
3) So-called Municipal bonds whose dividends/interest are usually exempt from Federal taxes in box 8.
IF they issue that form to you, they also send a copy to the IRS, and the IRS will eventually check your tax return against all the income information they receive from all sources, to make sure you reported your income properly.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*