VoIP stands for Voice Over Internet Protocol. It’s a way of making phone calls over the internet, rather than using regular landlines. Just like regular phone calls, these VoIP calls can be used to send messages like text messages, advertisements, and other types of communication. Unfortunately, some people misuse VoIP to send lots of unwanted messages, called "spam." This can be annoying, intrusive, and sometimes even illegal. To try to stop this, some companies have started making VoIP "spam filters" that try to stop you from getting too many VoIP spam messages.