Advantage: Using charts and graphs can help the audience grasp visually the message that has to be conveyed. Charts and graphs are especially useful if there will be a great deal of details that would normally take up too much time explaining and you need to compact the information to a visual summation. Knowing your audience helps creating the right type of charts and graphs to use. For example, if you are addressing a team of sales representative, you want to search for sales charts and graphs that typically a sales team will understand visually. When utilizing charts and graphs keep in mind that they are to be supplemental to using words. Charts and graphs can be very powerful in visual presentations if done effectively.
Disadvantage: There are many different formats that can be used in creating charts and graphs that could make it quite difficult or frustrating to choose the correct one to effectively use. Too many charts and graphs can come across to be very confusing, lack clarity or irrelevant.
The advantage to using graphs and charts is that they can display a lot of information is an easy to understand format. For example, a line graph is a great way to show trends over a period of time. You could put numbers in a table, but a line that is consistently going up is much more accessible at a quick glance. Bar graphs show comparison stats in a simple way, and pie charts display group breakdowns neatly as well.
The limitations of graphs and charts though is that there is always a limit to how much data they can show at a time. Additionally, it can be fairly simple to make a graph display information in a misleading way. By adjusting the Y axis values, a bar graph comparison can display the same information in two very different ways. In one graph with large axis values, the two bars might not look that much different. But if the Y axis is progressing by a value of 1, the one bar may tower over the other bar. It's misleading.