В чем разница между clauses of time and condition и object clauses?

conditionals First conditional If the photos are good, I'll send them to you. If you're not going, I'm not going to go either. If I haven't come back by 9.00 ,  start dinner without me. I'll have finished in an hour if  you don't disturb me. *You can use any present tense in the if clause and any future form or an imperative in the other clause. Извини я не знаю про clauses of time