Fish model explains the mapping between different stages of development and testing.
phase 1: informnation gathering takes place and here the BRS document is prepared.
phase 2: analysis takes place.During this phase,development people prepare SRS document which is a combination of functional requirement specification and system requirement specification.During this phase,testing people are going for reviews.
Phase-3: Design phase.here HLD and LLD high level design document and low level design documents are prepared by development team.Here , the testing people are going for prototype reviews.
phase-4: coding phase.White box testers start coding and white box testing is being conducted by testing team.
phase-5: testing phase.white box testing takes place by the black box test engineers.