>>4346512these days its often referred to weird high pitched jap songs or loli anime for some reason, but the closest parallel term in the west (its a jap word) would be a combination of analog horror and psychological horror
it literally means "electromagnetic wave"
usually it just refers to character thats insane, whether or not technology is involved
heres a few examples of denpa
>lain (the most well known example)>koishi>yume nikki and its fangames>cross channel>chaos;head>shimeji simulation>saya no uta