A Surface Mount Device (SMD) is a tiny electronic component designed to be mounted directly onto the surface of printed circuit boards (PCBs), rather than being inserted into holes as with traditional through-hole technology. SMDs allow for more compact and lightweight electronic assemblies, enabling higher circuit densities and improved performance. They are widely used in modern electronics, including computers, smartphones, and networking equipment. While SMDs themselves are not a cybersecurity technology, their use is relevant in the context of cybersecurity hardware, as compact and efficient circuit designs can impact device security, tamper resistance, and the implementation of cryptographic modules.