Yes, CompTIA Security+ expires every three years it's issued. For continuing your certification, you have three options, and they are:
- by taking up CertMaster CE Security+training course
- doing recertification of the latest release of CompTIA Security+ exam or higher CompTIA certifications
- Take up multiple qualifying activities and complete them to earn Continuing Education Units (CEUs) for recertification. You should earn 50 CEUs for recertification.
If you wish to break into the Cyber Security domain, I would recommend the CompTIA Security+ Training course and watch the Cyber Security Training video.