MYFICO.COM explains finance shopping here:
Hard inquiries are credit inquiries where a potential lender is reviewing your credit because you've applied for credit with them. These include credit checks when you've applied for an auto loan, mortgage or credit card. Each of these types of credit checks count as a single credit inquiry. One exception occurs when you are "rate shopping". That's a smart thing to do, and your FICO score considers all inquiries within a 45-day period for a mortgage, an auto loan or a student loan as a single credit inquiry. This same guideline also applies to a search for a rental property such as an apartment. These inquiries are usually recorded by the credit bureau as a type of real estate-related inquiry, so the FICO Score will treat them the same way. You can avoid lowering your FICO Score by doing your apartment hunting within a short period.