'랑' is a particle attached after a noun meaning 'and' or 'with'.
When to use
Talking with friends, Casual conversation, Friendly situations
The nuance
'랑' attaches after a noun to connect two or more items or indicate 'with'. It can be used regardless of whether the noun ends with a consonant or vowel. It is mainly used in spoken, casual contexts. In formal writing or speech, use '와/과' instead. Example: 친구랑 (with a friend), 책이랑 (and a book).
