WICP is the token version of ICP, each WICP token is backed by 1 ICP, users deposit 1 ICP into the WICP canister and get 1 WICP in return, users burn 1 WICP and get 1 ICP back. It is similar to Wrapped Ether(WETH).
Currently, convert ICP into WICP is not possible because canisters are not allowed to hold ICP on the Internet Computer, hopefully, this restriction will be lifted in the future by the DFINITY Foundation.
The DFinance DeFi products do not support ICP directly, but use WICP instead, users will be able to convert their ICP into WICP tokens when we launch the mainnet.
During testnet period, each user can claim some WICP test tokens, you can see it on the wallet page: