What font is the text in the current buffer?

To know what the font and what the glyph codes are, use C-u C-x = on the current character the point is on. You should see something like

character: i (105, #o151, #x69, U+0069)
charset: ascii (ASCII (ISO646 IRV))
code point: #x69
syntax: w which means: word
category: a:ASCII graphic characters 32-126 (ISO646 IRV:1983[4/0]) l:Latin
buffer code: #x69
file code: #x69 (encoded by coding system windows-1252-unix)
display: by this font (glyph code)
-outline-DejaVu Sans Mono-normal-r-normal-normal-16-120-96-96-c-*-iso8859-1 (#x69)

It can also be invoked as M-x describe-char.