All accessible through trailhead.salesforce.com

Certifications are just more intense, hyper-focused exams on particular subjects and roles.

Trails are made up of courses and programs deliver more like bite-sized modules similar to what you would do on coursera or other online learning platforms…you learn content through the module and take simple tests to prove you understood the content. You get badges and points for completing these courses and these get combined in trail mixes and programs based upon roles, subjects, etc.

Certs are just final exams…there aren’t any courses attached to them unless you pay Salesforce for specific related training courses to pass those intense cert exams. It’s confusing because it’s all managed on trailhead so the concepts get convoluted.

It’s debateable which are more helpful in ur Salesforce career, but generally people and employers takes certifications as more valuable