The Duke of Edinburgh, Colonel-in-Chief of the Royal Canadian Regiment, presenting the 3rd Battalion with their Regimental Colours in 2013

The Colonel-in-Chief of a regiment is its (usually royal) patron, who has a ceremonial role in the life of the regiment. They do not have an operational role, or the right to issue orders, but are kept informed of all important activities of the regiment and pay occasional visits to its units. The chief purpose of the Colonel-in-Chief is to maintain a direct link between the regiment and the royal family.[

Source: wikipedia.com