Three kinds of software
Three things sold as bulk WhatsApp software in Jaipur
They look alike on a listing site. This is how each behaves for a business that sends hundreds of messages at a time.
1 Programs for one PC
Installed on a shop or office computer, using WhatsApp Web on a personal SIM. Bought once, often cheaply, but heavy sending this way is what gets numbers blocked, and nothing runs while that PC is off.
2 Browser add-ons
A Chrome extension that drives WhatsApp Web from a single tab. It shares the desktop program's block risk, needs the laptop awake, and lets only one person in at a time.
3 Cloud platforms on the official API
Software hosted on servers and wired straight into Meta's own platform. Open it in any browser, let several staff onto one number, and schedule sends that run with every screen closed. WappBlaster is built this way.