Bitcoin BEP2 (BTCB) is a token that is pegged to BTC at a rate of 1 BTCB = 1 BTC, issued on the Binance Chain by Binance.
Binance backs each BTCB token with equivalent amount of BTC in a reserve which can be validated with in the following address
BTC Reserve Address: https://blockchair.com/bitcoin/address/3LYJfcfHPXYJreMsASk2jkn69LWEYKzexb
BTCB Issuance Address: https://explorer.binance.org/asset/BTCB-1DE
The objective of issuing BTCB is to bring Bitcoin liquidity to the Binance Chain so users are able to trade Binance Chain issued tokens against Bitcoin, especially on the Binance DEX.