Hello!
Search engine marketing and Pay Per Click can not exist separately. If, of course, we strive for efficiency.
Both parts of resource promotion complement each other. Just as there is no point in PPC before building an index presence, index presence depends on behavioral factors, statistics on which can be accelerated using PPC.
Achieve a balance between cost and efficiency. Let paid visitors find you on the Internet and form an opinion about your company.
To answer your question directly - SEO is part of SEM. PPC is advertising that can attract visitors and also generate behavioral statistics. And if your SEM is good, PPL will benefit you. If SEM is bad, it will do harm.