This review provides a comprehensive overview of FBG sensor technology, focusing on their operating principles, key advantages such as high sensitivity and immunity to electromagnetic interference, and common challenges like temperature-strain cross-sensitivity and the high. This review provides a comprehensive overview of FBG sensor technology, focusing on their operating principles, key advantages such as high sensitivity and immunity to electromagnetic interference, and common challenges like temperature-strain cross-sensitivity and the high. Fiber Bragg grating (FBG) sensors have emerged as advanced tools for monitoring a wide range of physical parameters in various fields, including structural health, aerospace, biochemical, and environmental applications. These microscopic structures within optical fibers have become the bedrock of cutting-edge sensor. Abstract: Fiber-optic sensing of temperature and strain over many advantages over electronic sensors. Fiber-Bragg-Gratings (FBGs) are used for spot sensing, whereas Rayleigh, Brillouin and Raman scattering are used for distributed sensing in long fibers. In this article, these sensor principles are. This article explains what fiber Bragg gratings (FBGs) are: periodic modulations of the refractive index in a fiber core which reflect a narrow wavelength band according to the Bragg condition $lambda =2{textstyle phantom{rule{0. 222em}{0ex}}}{n}_{text{eff}}{textstyle.