Introns are non-coding sequences found within genes in DNA. They are segments that do not code for proteins and are typically removed during the process of RNA splicing. This process occurs after transcription, where the DNA is copied into messenger RNA (mRNA). Despite not coding for proteins, introns may play important roles in gene regulation and the evolution of new genes. Their presence can influence how genes are expressed and can contribute to the diversity of proteins produced by a single gene through alternative splicing.