An e-signature can be typed and is equally as legally binding as a document signed by hand. There are laws making it secure, protecting businesses' and individuals’ interests.
You can use Microsoft Word or Adobe Acrobat if you want to have an e-signature for free. If you want to send them, you can commonly use Messenger Apps or through email.
An e-signature is a digital method of signing documents that shows that you agree to what's written on the paper. It is equally the same as signing documents on paper, but electronically.