With the signature component, you can let users sign for things in your apps. When someone signs, the signature component generates an image and writes the link to that image to the sheet. It will then display their signature in the component.
The signature component has three properties.
The Placeholder, which displays in the component before a signature exists.
The Message, which appears under the signature whilst a user is signing
The Signature URL, which is the column the signature image will be written to.
If you want each user's signature to be specific to them on every item, then you will want to create a User Specific Column for the Signature URL.
The signature component is particularly useful in forms. Bear in mind that it will not write to the sheet until the form is submitted.