This volume gathers together revised versions of the papers presented at the ECREA Radio Research Section Conference held in Lublin, Poland, in September 2017. The book highlights what radio actually is – a medium created to connect different places at a distance. Subtle but pervasive, simple but graceful, radio builds affective relations, either between listeners and the world or between listeners themselves. The word "relations" is plural. It suggests the idea that radio is both an economic activity – related to technology, production, working routines and business – and a cultural industry – related to aesthetics, art, social interaction, education and politics. Since relations are relevantly human, we can explore how radio appeals to personal commitment and can reinforce a sense of community too. The unique value of this book lies both in erudite essays of Sean Street and Enrico Menduni, world-famous figures of radio research, and in perspectives sketched by brilliant young radio practitioners and researchers. The diverse views on radio communications from authors across the different regions of the world including Brazil, Canada, Italy, Poland, France, Hungary, Spain and the UK collected here will certainly inspire radio researchers, media historians, sociologists and journalism students.