Meaning of the word "sea change" in English

What does "sea change" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

sea change

US /ˈsiː ˌtʃeɪndʒ/
UK /ˈsiː ˌtʃeɪndʒ/
"sea change" picture

Noun

a profound or notable transformation

Example:
The internet brought about a sea change in how we communicate.
There's been a sea change in public opinion on the issue.