See https://www.irs.gov/publications/p538#en_US_202112_publink1000270638

• A cash basis taxpayer reports income when it is actually received, and reports expenses when they are paid. The majority of people who file individual income tax returns are cash basis taxpayers.
• Accrual basis taxpayers compute income when they actually earn it or became entitled to it. Their deductions are computed based on when those debts were incurred, but not necessarily paid.