「しばしば」は「よく」「何度も」という意味で、同じことが何回も起こるときに使います。

"しばしば" means "often" or "many times," used when the same thing happens repeatedly.

話し言葉より、少しかたい文章でよく見られる言葉です。

This word is more commonly seen in somewhat formal writing than in spoken language.