The importance of copy

Copy includes all worded content in a magazine. It's important because it conveys information the clearest. Images can only explain so much, there is also room for misinterpretation. Copy consists of words that say exactly what they mean, leaving little room for confusion. It's the most effective way to communicate information.

From: Cook's Country

Without the caption, it would be difficult to understand what the image depicts. The caption explains who these people are and what they are doing.