Slicers in Power BI are the visual filter present on the report page. It allows us to sort and filter information present in the packed report. Unlike filters, it is present as a visual on the report.
You can analyze the report and can select the values from it. Let's say you have a sales report; you can make a slicer of years and can select the year for which you want to see the sales metrics. The visuals of the report will automatically change to show the information of the respective year.