Daedalus is a Cardano Wallet made by IOG (the developing company behind Cardano). It is a desktop application, which works with all major Operating Systems (Windows, MacOS and Linux).
Daedalus is a full node wallet. This means that unlike light wallets (e.g.Yoroi, Adalite etc.) Daedalus downloads a full copy of the Cardano blockchain and independently validates every transaction in its history. That way you get maximum security and completely trustless operation, without centrally hosted 3rd party servers.
Daedalus can be downloaded here: https://daedaluswallet.io/
Yoroi is a Cardano Wallet developed by Emurgo, the commercial partner for Cardano. It is available as an extension for all major browsers (Chrome, Firefox, Edge) and as a mobile app for both Android and iOS.
Yoroi is a light wallet for Cardano. It’s simple, fast and secure. Yoroi is an Emurgo product, engineered by IOHK. And it follows best practices for software in the industry including a comprehensive security audit. Daedalus and Yoroi are complements to what they try to achieve. Yoroi looks to be a day to day wallet for a Cardano user.
Yoroi can be downloaded here: https://yoroi-wallet.com/
Which wallet you choose to install is ultimately up to you. Considerations that may help you choose are:
System requirements (check these carefully);
Ease of use (heavily dependent on your confidence around new software);
Appeal of interface (entirely subjective).