Subdomains are the text before a domain, for example, race.declan.fun or snow.declan.fun are different from the main domain, declan.fun, so they are subdomains.
WEATHER:
weather.declan.fun
snow.declan.fun
GAMES (or includes games):
race.declan.fun
countdown.declan.fun
PROJECTS:
test.declan.fun
cat.declan.fun
audio.declan.fun
PERSONAL:
photos.declan.fun