Cycling infrastructure can be many things - a section of bikeway, showers in a workplace, dedicated cycle lanes/routes, signage on a bike path, bike racks at a cafe, bicycle bridges, bicycle lockers at a train station, bicycle safety zones at traffic lights, etc.
Sometimes it can even be a simple thing like a temporary safe detour around work on a designated cycle route.
These types of infrastructure will, generally, help to make cycling safer and more accessible. Infrastructure doesn’t have to be “big picture” projects to be successful. A sign of successful infrastructure is usually how many bicycle riders actually use it. Jan's photo of the maintenance station at Southbank is a case in point. Some of you didn't know this existed, but now you do and you can make use of it should the need arise.
Our photo shows bicycle parking in The Netherlands - now that's infrastructure!