Transposable elements (TEs) are major components of eukaryotic genomes, and their impact on genome evolution, function, and disease remains a subject of intense study. TEs come in various forms and shapes, classified into two major classes based on their transposition mechanisms: retrotransposons (Class 1) and DNA transposons (Class 2). TEs are not randomly distributed in the genome but exhibit preferences for specific genomic locations, influenced by selective forces that balance propagation and host fitness. They are extensive sources of mutations and genetic polymorphisms, contributing to genetic diversity and disease. TEs also play a role in genome rearrangements and structural variations, and they can contribute to unique chromosome features. The expression and repression of TEs are finely balanced to avoid fitness disadvantages for the host. TEs can act as insertional mutagens in both germline and somatic cells, causing genetic diseases and contributing to cancer. Additionally, TEs can provide raw material for the emergence of protein-coding genes and non-coding RNAs, which can take on important cellular functions. They also contribute to cis-regulatory DNA elements and modify transcriptional networks. Analyzing TEs requires specialized tools due to their repetitive nature, and ongoing research aims to better understand their cellular functions and evolutionary roles.Transposable elements (TEs) are major components of eukaryotic genomes, and their impact on genome evolution, function, and disease remains a subject of intense study. TEs come in various forms and shapes, classified into two major classes based on their transposition mechanisms: retrotransposons (Class 1) and DNA transposons (Class 2). TEs are not randomly distributed in the genome but exhibit preferences for specific genomic locations, influenced by selective forces that balance propagation and host fitness. They are extensive sources of mutations and genetic polymorphisms, contributing to genetic diversity and disease. TEs also play a role in genome rearrangements and structural variations, and they can contribute to unique chromosome features. The expression and repression of TEs are finely balanced to avoid fitness disadvantages for the host. TEs can act as insertional mutagens in both germline and somatic cells, causing genetic diseases and contributing to cancer. Additionally, TEs can provide raw material for the emergence of protein-coding genes and non-coding RNAs, which can take on important cellular functions. They also contribute to cis-regulatory DNA elements and modify transcriptional networks. Analyzing TEs requires specialized tools due to their repetitive nature, and ongoing research aims to better understand their cellular functions and evolutionary roles.