Both the Excel sheets and PowerPoint slides are used side by side and, we often copy the tables and charts from Excel, and paste them into PowerPoint slides to make a slideshow presentation.

Therefore, using Excel to first create your charts and then importing them into PowerPoint allows you to create presentations with chart data that is more accurate.

Copy graphs with lot more professional and cleaner look in your presentations from your Excel book, using Ctrl+Alt+V - Windows Enhanced MetaFile.