Ice found at the sea surface that has originated from the freezing of seawater. Sea ice may be discontinuous pieces  moved on the ocean surface by wind and currents , or a motionless sheet attached to the coast . Sea ice concentration is the fraction of the ocean covered by ice. Sea ice less than 1 year old is called first-year ice. Perennial ice is sea ice that survives at least one summer. It may be subdivided into second-year ice and multi-year ice. where multi-year ice has survived at least two summers.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report