Information retrieval is often a continuous process during which you will consider, reconsider and refine your research problem, use various different information resources, information retrieval techniques and library services and evaluate the information you find. The figure below implies that the stages follow each other during the process, but in reality they are often active simultaneously and you usually will repeat some stages during the same information retrieval process.
Source: Aalto University Library. Guide to information retrieval.
The different stages of the information retrieval process are: