Metaphor is a figurative language that is used to compare two unlike things. Unlike similie, which uses words 'as' and 'like' to compare, metaphor compares implicitly.
The given sentence, "gadgets isolate us from the rest of the world" is an example of metaphor. The two things compared in this sentence is gadgets and isolate. Gadgets are compared to isolation. When someone is addicted to using gadgets, he/she separates herself/himself from the rest of the world.
