Visio is the Microsoft diagram creation software package. It's not included in Microsoft Office, but it is fully compatible with Office programs such as PowerPoint. You can convert a Visio drawing to work in PowerPoint by copying and pasting it in and then ungrouping the elements of the drawing. You must have Visio installed to convert the drawing.
Open both Visio and PowerPoint. Click on the Visio diagram that you want to convert to PowerPoint. Click on the "Home" tab and then click "Copy" button in the "Clipboard" section on the left side of the ribbon.
Switch to PowerPoint and click on the slide where you want the diagram. Click on the "Home" tab and then click on the "Paste" button in the "Clipboard" group to paste the Visio diagram into your presentation as an embeded Visio object. With the object embedded, if you want to edit it, Visio will open, but a separate copy the diagram is saved within the PowerPoint presentation.
Click the diagram in PowerPoint. Click on the "Home" tab and then click on the "Arrange" button in the "Drawing" section. Click "Ungroup." This separates the elements of the Visio diagram into separate objects that can be edited within PowerPoint. The diagram is no longer a Visio object and has been converted to PowerPoint.
Some of the subparts of the diagram might still be grouped as a Visio object after the first "Ungroup" command. Repeat as necessary to convert everything to PowerPoint. You can link a Visio object to your PowerPoint presentation instead of inserting and converting it, so that any changes made to the Visio diagram will be reflected in the PowerPoint version as well. After you copy it in Visio, click the arrow under the "Paste" button in PowerPoint and choose "Paste Special." Select "Visio Object" from the list and click the "Paste Link" radio button on the left before clicking "OK." If you send a PowerPoint with an embeded or linked Visio object, only people who also have Visio will be able to edit it.