Linux v/s Windows

It is really important to have online protection before we operate online. In some situations, our computers can be quickly infected with online threats. Last day, I read a blog on this topic What Can You Do To Protect Yourself From Spyware, Malware And Ransomware? | NCI. They have listed some points to protect our computers. I have heard that Linux operating systems are safer than Windows operating systems for online activities. Is that true? Then what is the reason behind this?