A plagiarism checker is a tool designed to identify instances of copied or unoriginal content in written work. It compares the submitted text against a vast database of sources, including academic papers, websites, and books, to detect similarities. This helps ensure that the work is original and properly attributed, which is essential in academic and professional settings. These tools are commonly used by students, educators, and writers to maintain integrity in their work. By using a plagiarism checker, individuals can avoid unintentional plagiarism and improve their writing skills by learning how to paraphrase and cite sources correctly.