Omics technologies have revolutionized research across diverse fields, and their increasing use in microbiology has provided new opportunities for understanding microbial life. These methods enable detailed investigation of the molecular biology of individual organisms as well as the complex interactions within microbial communities. In this chapter, we describe key single-organism omics approaches, including genomics, transcriptomics, proteomics, and metabolomics, as well as meta-omics techniques such as metagenomics, metatranscriptomics, metaproteomics, and meta-metabolomics. We also discuss integrative multi-omics strategies for studying microbial ecosystems. For each omics method, we outline its main features, experimental and bioinformatic workflows, major applications, and commonly used computational tools, thereby providing a practical guide for researchers aiming to explore microbial structure, function and interactions at multiple molecular levels.