The attributes are considered as the qualifying parameters of the users based on which you can easily categorize a particular set of users.
E.g. Name, email, Tags, Country & many more.
Here's an example: let's say you wish to send a Broadcast to new leads. While adding the leads to AiSensy, you assign a Tag named Lead to all the contacts & upload the contacts to AiSensy.
Here, the tag Lead is a defining attribute using which you can filter a set of users while Broadcasting. These attributes can very well be collected by a WhatsApp Chatbot.