There are three kinds of theft considered in household contents insurance;
Burglary is where someone breaks into your apartment or uses a fake key or has illegally obtained a real key entry to gain entry without your authorization.
Robbery is where someone uses violence or the threat of violence to take your belongings.
Theft (or simple theft as it's called) is when someone takes your belongings without you knowing, for example, pickpocketing.
What's covered by my policy?
Household contents insurance covers burglary and robbery, but simple theft is only covered in specific situations for example while you're staying in a hospital or in ship cabins and sleeping car compartments.
Your bike is also covered from simple theft if you've selected either the extended or comprehensive bike coverage. Simple bike theft is not covered under the basic policy.