Abstract With the increasing need of more interactive and personalized intelligent systems, the uses of applied psychology and psychophysiological signals in modern technologies are also growing proportionally. There are many available instruments such as electroencephalogram, functional magnetic resonance imaging, electrocorticography, and electrodermal activity (EDA), which effectively collect neurological signals and help us to study and analyze different phenomena of brain and mind. But to make most of the available signals and methodologies, researchers required a thorough comprehension of these fields and background knowledge (physiological and psychophysiological significance) of these signals. Though most of abovementioned signals have been studied rigorously and there are thousands of documentations out there over Internet. But this is not the case with all of the psychophysiological signals. This makes the things little complicated for researchers coming from different backgrounds and fields and they find it difficult to get going. One such signal is EDA signal or galvanic skin response. EDA has been in use for last 100 years or so but failed to grab the attention of the researchers until recent times. Though the portability and simplicity of the device make it quite popular among the modern researchers, the underlying physiological significances and cognitive significances are still the matter of argument for researchers. If we discuss the last 20 years, then the use of EDA signal in psychological as well as human–computer interaction–based studies show an upward curve. But in spite of such high popularity and use, the underlying phenomena of EDA are still not fully understood. There are several reasons behind this lack of clarity, and among them the most prominent is dearth of well-written documentation (except the most popular book on EDA written by Boucsein came out in early 1992) on this particular signal. But researchers and students coming from different backgrounds need something short as well as stimulating documentation to start doing experiment with EDA signals. The overall motivation of this chapter is to introduce the readers to the broad spectrum of EDA signal and encourage them in EDA research. We have tried to provide a short theoretical physiological and psychological significance of EDA signals, which will help the researchers to get some background knowledge on EDA signal. Furthermore, we have discussed the need of good experiment design and factors that researchers must consider during an experiment designing. Last but not the least is how to preprocess and analyze the collected EDA signal. In a nutshell, readers coming from different backgrounds can use this chapter as a starting point of their study and can get an overview of all the essential factors related to EDA to carry out their research.