Meaning of the word "know something like the back of your hand" in English

What does "know something like the back of your hand" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

know something like the back of your hand

US /noʊ ˈsʌmθɪŋ laɪk ðə bæk əv jʊər hænd/
UK /nəʊ ˈsʌmθɪŋ laɪk ðə bæk əv jɔː hænd/
"know something like the back of your hand" picture

Idiom

to know a place or subject very well

Example:
I've lived in this city my whole life, so I know it like the back of my hand.
Our tour guide knew the historical facts like the back of his hand.