Also, you can see the
signer type. The signer type represents sender authority. In other words - using signer means accessing the sender's address and resources. It has no direct relation to signatures or literally signing, in terms of Move VM it simply represents sender. If you are going to use the
signer type in your script, it must be the first argument in your main function. Important: you don't need to provide an argument for signer type when executing a script, as it will be done automatically.