如果要暑期实习必须申请CPT吗？

我对OPT和CPT不太了解，只知道可以用来延长身份
我看到学校的CPT是： Graduate students with coursework remaining can only
participate in full-time CPT during official school breaks (including Winter
Session).
目前我还是研一。我的理解是只要找到了暑期实习工作是必须申请CPT的对吗？
谢谢各位！