In this tutorial we will learn to extract the spectral signatures of different land cover classes using the Semiautomatic Classification plugin in QGIS 3.16 that allows the supervised and unsupervised classification of remote sensing images.

Satellite Data used: Landsat 8
Video on how to download Landsat 8 in QGIS :    • Download Satellite Data using QGIS | ...  

How to perform Supervised classification in QGIS:    • Supervised Classification in QGIS