Your digital profile isn't just your search history. It includes your passwords, intimate emails, contacts, location history, the metadata of your daily life (dates, times, durations etc) and a whole lot more. Your data is then sold to brokers and collected by governments, used to surveil you, it can be exposed in breaches and will be used to sell to you.
By reducing the amount of data you leak unknowingly or give away freely without thinking, you can limit the effects of data collection.
If this is news to you and a little confusing, have a quick read of Understanding Your Digital Profile and if you do nothing else go to 10 Quick Digital Privacy Wins and start reclaiming your digital privacy.
Below are a number of practical steps to start reclaiming your digital privacy.