The use of digital images is exponentially increased due to the availability of various image capturing devices and the provision of transmitting them with less expense. Digital images are used for various purposes such as personal, entertainment, medical diagnosis, fashion design, forensic analysis, etc. The retrieval of relevant images from a huge volume of images is a tremendous task. Content-based image retrieval (CBIR) is a solution to retrieve relevant images from a pool of images by considering a query image. In a CBIR scheme, the user will give a query image and the system supposes to return a set of the image which are very similar to the query image. The CBIR schemes use classification models and the visual features of the images while ranking and retrieving the images from the image pool. This manuscript discusses the overview of a CBIR scheme, its application domains, the existing approaches in this domain and various datasets available for the research in this domain. The manuscript has also listed a set of challenges in this domain so that future works can be focused on this area.