The adjective embedded describes something that is encased in a surrounding substance. On a walking tour of Fredericksburg, Virginia, you can see buildings with embedded Civil War cannonballs.
Embedded also means to insert as part of a whole. In wartime, embedded journalists are stationed with military units so that they can make first-hand reports on the news, and so that viewers can have a more in-depth understanding of issues facing the soldiers. This use arose during the Iraq war in 2003. Embedded comes from the verb embed, which originally applied to materials embedded in rocks, such as fossils.