Junction-less field effect transistors, also known as JLFETs, are widely regarded as the most promising candidate to replace the conventional metal oxide semiconductor field effect transistors (MOSFETs) currently used in integrated circuit technology. These FETs are less likely to have short channel effects (SCEs) than devices with junctions, as shown by their remarkable subthreshold slope and drain induced barrier lowering (DIBL). Due to its gate coupling, the gate-all-around (GAA) JLFET is a better contender to uphold Moore's law than other existing device architectures and regular JLFET, allowing more precise channel tuning. Among GAA and JLFET at the same technology node, the SCE is kept to a minimum in GAA. Until now, no comprehensive review of the various JLFET structures and modeling techniques for the analysis of their various device parameters have been provided in a single resource. From device evaluation and application to qualitative and quantitative parameter analysis studies likewise subthreshold swing, DIBL and switching ratio, this review provides comprehensive information on the various structures of Junctionless and GAA JLFETs. Furthermore, various device modeling techniques of JLFETs for enhancing the device's characteristics and its application in various semiconductor industries are provided.