In most cases, the range_lookup is used as FALSE (an exact match). The default for this parameter is TRUE - it is less commonly used in this form, but this example shows one usecase. A supermarket gives a bonus based on the customers monthly spend.
If the customer spends 250 EUR or more in a month, they get 1% bonus; 500 EUR or more gives 2.5% etc. Of course, the customer won't always spend exactly one of the values in the table!
=VLOOKUP(261,$A$2:$B$6,2,TRUE)
In this mode, the VLOOKUP will find the first value in column A
(following bottom-up steps) less than or equal to the value 261 -> i.e. we will get the 1%
value returned. For this non-exact match, the table must be sorted in ascending order of the first column.