VLOOKUP is a built-in function in Microsoft Excel that allows users to search for specific information in a table or range by row. It is commonly used to retrieve data from a large dataset or to consolidate data from multiple sources. Here are the basic steps to use VLOOKUP in Excel:

1. In the Formula Bar, type "=VLOOKUP()".
2. Enter the lookup value, which is the value you want to search for in the first column of the table or range.
3. Enter the table array or lookup table, which is the range of data you want to search.
4. Enter the column number in the range containing the value to return.
5. Indicate whether you want an approximate or exact match by entering 1/TRUE or 0/FALSE.

It is important to note that the column which holds the data used to lookup must always be to the left. VLOOKUP is commonly used for data retrieval and analysis tasks. It is a powerful tool that can save time and effort when working with large datasets. However, it has some limitations, such as the inability to search for data horizontally or to search for multiple criteria at once. In such cases, other functions like INDEX and MATCH or the new XLOOKUP function can be used.