What does the VLOOKUP function primarily accomplish?

The VLOOKUP function is designed to search for a specific value within the leftmost column of a designated table array and then retrieve a corresponding value from a specified column in the same row. This functionality is particularly useful when you have large data sets and need to find related information quickly. For example, if you have a table of employee data where the first column contains employee IDs and subsequent columns contain their names, departments, and salaries, VLOOKUP can be used to look up an employee ID and return their name or salary. This makes it invaluable for data retrieval tasks in spreadsheets.

The other options describe functions that do not pertain to VLOOKUP: the second option refers to horizontal searches, which is not what VLOOKUP does as it strictly works vertically. Counting items in a column is a task that might involve the COUNT or COUNTA functions rather than VLOOKUP. Lastly, comparing data across worksheets typically involves functions like MATCH or specific lookup and comparison strategies rather than the direct capabilities of VLOOKUP.