The first step to unravel a material¿s nature is to understand its morphology. Today, researchers leverage several characterization techniques to analyze the morphology of samples. In that perspective, the first chapter of the current book is focused on different morphological analytical techniques including optical microscopy, scanning electron microscopy, and transmission electron microscopy as a means to explore sample¿s features, including shape, texture, and structure. Each section includes the history and the evolution of the technique, the mechanism of operation, advantages and limitations, and some example applications mainly focused on the biosensing field. The chapter also presents the main differences between light microscopy and electron microscopy techniques. Moreover, common errors that are encountered during the image acquisition process are also presented in the troubleshooting section, along with causes and possible solutions to each problem.