Ferdinand de Saussure was a Swiss linguist born in 1857, known for his foundational work in the field of linguistics. His ideas laid the groundwork for modern linguistic theory, particularly through his concepts of the signifier and signified, which describe how words and their meanings are connected. Saussure's most influential work, "Course in General Linguistics," published posthumously in 1916, emphasized the importance of studying language as a system of signs. He introduced the idea of langue (the abstract system of language) and parole (individual speech acts), shaping the way we understand language and communication today.