Broken Concrete is also known as Urbanite. I love using the material to build pathways and walls. The cement industry produces a lot of Carbon Dioxide. Re-using existing concrete is an environmentally-friendly option for paving needs, and it can look awesome!
This pathway looks a lot like natural stone in person. It is laid permanently in mortar.
Alternatively pathways can be laid in sand or decomposed granite, or broken concrete pavers can be surrounded with pea gravel or larger stones. All of these options create permeable pathways, which are more environmentally friendly than using cement between joints. The material will look different depending on how it's installed.
Many people use gravel for pathways, and even though gravel can be very pretty and appropriate for certain situations, it is not kid friendly for scooters and trikes, etc. Here's a recent project where I suggested we replace a gravel pathway and patio with Broken Concrete in Decomposed Granite. Now the children of the house can ride their tricycles along this path.
Broken concrete or any other paving material is usually more successful when installed by professionals. Laying the varied shapes in a pleasant pattern and getting a perfect level on each piece can be quite challenging for the inexperienced person. It also helps to have a pro pick out the broken concrete to make sure it is sound. Not all old concrete is worth re-using.
Here is a broken concrete pathway that serves aesthetically as a dry stream bed. The client wanted to use gravel with the broken concrete, and that is fine for this application because this is a pathway to the side of the house, and is not in constant use. It's more of a focal point from the path to the front door. The gravel gives the look she wanted, a nice contrast to the plantings in this former lawn area. However if this were a main pathway -- to the front door, for instance -- I would not suggest gravel because it can make a path along a slope like this a bit slippery. For a slope, you might want to install the broken concrete in cement. The first photo shows one way of doing that.