One never touches your score. The other counts for 12 months.
Checking your own report, pre-screened offers, account reviews — soft inquiries never affect your score, ever.
Applying for credit triggers a hard inquiry: about 10% of a FICO Score is new credit, and one inquiry often costs less than five points.
FICO counts a hard inquiry for 12 months. It stays visible on your report for two years.
Mortgage, auto, and student loan inquiries inside a short window (14 days in older FICO versions, up to 45 in newer ones) count as a single inquiry.
Hypothetical example: on a $25,000, 5-year car loan, landing 8% instead of 9% APR saves $722.94 in interest — far more than one grouped inquiry costs.
The grouping never applies to credit cards. Five card applications in one weekend = five separate inquiries.