Excel's functionality includes chart options you can insert to add a title directly onto a line graph, so that you don't have to insert extra text boxes or type into the cells around the graph.

How to Add Notes to an Excel Chart. Microsoft Excel's quick-format chart and graph features offer a way to instantly convert your data-filled cells into a visual representation such as a pie chart ...

This post shows how to add Alt Text to Images, Charts, Objects & PivotTables in Excel. Alt Text provides useful information to persons with disabilities.