• puts: Outputs value with newline, returns nil, calls .to_s
• print: Outputs value without newline, returns nil, calls .to_s
• p: Outputs inspected value with newline, returns the value, calls .inspect

puts "Hello"    # Hello\n (returns nil)
print "Hello"   # Hello (returns nil)
p "Hello"       # "Hello"\n (returns "Hello")