directories: current & downwards (recursively)
dates: Last 2 days.
Size >= 10k
find . -type f -mtime -2 -size +10k -name *.rb
for small files, or -100c for less than 100 characters
mtime is always number of days, e.g. "modified in the last 10 days, look in current directory and below.
find . * -mtime -10
ctime = created
atime = accessed