Transposable elements (TEs) are major components of eukaryotic genomes and play significant roles in genome evolution, function, and disease. This review outlines ten key points about TEs. First, TEs come in various forms, including retrotransposons and DNA transposons, with complex classifications based on their mechanisms and evolutionary origins. Second, TEs are not randomly distributed in the genome but prefer specific genomic regions, influenced by selective pressures. Third, TEs are a major source of mutations and genetic polymorphisms, contributing to genetic diversity. Fourth, TEs can be horizontally transferred between species, influencing genome evolution. Fifth, TEs are associated with genome rearrangements and unique chromosome features, such as telomere maintenance. Sixth, TEs must balance expression and repression to persist in evolution. Seventh, TEs are insertional mutagens in both germline and soma, causing genetic diseases. Eighth, TEs can be harmful without transposition, affecting host gene expression and causing immune responses. Ninth, TEs contribute to the production of coding and non-coding RNAs, some of which have essential cellular functions. Tenth, TEs provide cis-regulatory elements that influence gene expression and transcriptional networks. Finally, analyzing TEs requires specialized tools due to their repetitive nature. Understanding TEs is crucial for comprehending their impact on organismal biology and for developing strategies to manage their activity.Transposable elements (TEs) are major components of eukaryotic genomes and play significant roles in genome evolution, function, and disease. This review outlines ten key points about TEs. First, TEs come in various forms, including retrotransposons and DNA transposons, with complex classifications based on their mechanisms and evolutionary origins. Second, TEs are not randomly distributed in the genome but prefer specific genomic regions, influenced by selective pressures. Third, TEs are a major source of mutations and genetic polymorphisms, contributing to genetic diversity. Fourth, TEs can be horizontally transferred between species, influencing genome evolution. Fifth, TEs are associated with genome rearrangements and unique chromosome features, such as telomere maintenance. Sixth, TEs must balance expression and repression to persist in evolution. Seventh, TEs are insertional mutagens in both germline and soma, causing genetic diseases. Eighth, TEs can be harmful without transposition, affecting host gene expression and causing immune responses. Ninth, TEs contribute to the production of coding and non-coding RNAs, some of which have essential cellular functions. Tenth, TEs provide cis-regulatory elements that influence gene expression and transcriptional networks. Finally, analyzing TEs requires specialized tools due to their repetitive nature. Understanding TEs is crucial for comprehending their impact on organismal biology and for developing strategies to manage their activity.