Adding captions to your Instagram photos can help you get more followers and more exposure on Instagram. A good Instagram photo caption will definitely get more likes and comments. With the recent changes to Instagram's algorithm, posts now appear in feeds "based on the likelihood [the audience] will be interested in the content." That means that a photo or video with lots of comments and Likes has a better chance of appearing at, or near the top of your followers' home stream.
If you want to add a caption to your Instagram photos before sharing them with friends and followers is easy. It is the default process i.e.