The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flowchart is a way of reporting how you have arrived at the final number of results included in your study.
There are two versions of PRISMA - 2009 and 2020. The 2009 version is most commonly used but you may be asked to use the 2020 version. Please speak to your module leader/supervisor if you are unsure about which one to use as there are differences between the two.
The PRISMA flow diagram shows the relevant stages the information goes through as part of the systematic review process.