1. Hard Inquiries: Hard inquiries occur when a lender or creditor checks your credit report as a result of a credit application. These inquiries can impact your credit score and are visible to other lenders. Examples include applying for a credit card, a car loan, or a mortgage.
2. Soft Inquiries: Soft inquiries are not related to credit applications and do not affect your credit score. They occur when you check your own credit report or when a potential employer or landlord performs a background check. Soft inquiries are only visible to you and not to other lenders.
3. Promotional Inquiries: Promotional inquiries happen when credit card companies or lenders check your credit to preapprove you for offers. These inquiries are usually soft inquiries and do not impact your credit score. Examples include receiving preapproved credit card offers or loan offers in the mail.
4. Account Review Inquiries: Account review inquiries occur when a lender or creditor checks your credit report periodically to review your existing accounts. These inquiries are typically soft inquiries and do not affect your credit score. Examples include periodic credit limit increases or account maintenance checks.

It's important to note that while hard inquiries can have a temporary negative impact on your credit score, the impact is usually small and diminishes over time. It's generally recommended to limit the number of hard inquiries you have within a short period to avoid potential negative effects on your credit.

For more information, you can refer to reputable sources such as:

• Experian - Hard vs. Soft Inquiries on Your Credit Report
• Equifax - Understanding Hard Inquiries on Your Credit Report
• TransUnion - Investigate Credit Report Inquiries

I hope this information helps! Let me know if you have any other questions.