There are various ways to select features in ArcMap. One way is to select features through an attribute table. From a table, you can interactively select records by pointing at them, or you can select those records that meet some criteria; for example, find all cities with a population greater than one million.
Once you've defined a selection, you'll see those features highlighted on your map. For example, suppose you wanted to find the locations of the five cities with the largest populations. You would sort the records in the table in descending order based on population, then select the top five records in the table to see them highlighted on the map. You can add to your selected set using any other ArcMap selection methods.
Many of the ways you can work with selections in the Table window have keyboard or mouse shortcuts. To learn about them, see Keyboard shortcuts for working with tables.