Ribosomal RNA is an essential component of ribosomes, which are responsible for synthesizing proteins. There are different types of ribosomal RNA, each with a specific function. For example, 16S RNA is found in the small subunit of bacterial ribosomes, while 18S RNA is found in the small subunit of eukaryotic ribosomes. Other synonyms for ribosomal RNA include rRNA and ribosomal nucleic acid. The term "non-coding RNA" is also used to describe ribosomal RNA, as it is not translated into protein but plays a crucial role in protein synthesis. Overall, ribosomal RNA is a fundamental component of cells and essential for life.