Hi, I am always confused when two indifference curve are convex, what does it mean about two goods? When the curve is concave , what does it mean? When it's L shaped or straight line, what does it mean?

what does the indifference curve looks like for a pair of two goods, a bad and good, bad and bad,

eg x good, y good,

x bad, y good

x good, y bad

x bad , y bad

please give examples and good graphs, thank you!