Which is best way

For any application which method is better either image search or OCR …please give me explanation also.

eggPlant is an image based testing tool, so when you can use captured images, it is generally recommended to do so. However, the OCR is a great tool for working with dynamic text in situations where images cannot be captured. These two approaches are best used together.
The OCR uses an interpretive algorithm to decipher pixel patterns on the screen, so the searches can be slower than image searches. For best performance in terms of speed, image searches or OCR searches within a confined searchRectangle are your best bet.