Concrete drilling or cutting of any sort may not seem very complicated; you can use a special concrete drill and make quick work of cutting through a basement wall or garage floor in order to run conduit or pipes through, or so it would seem. However, concrete drilling is always best left to a professional because it's usually much more complicated than you may realize. Note why this is and why professional contractors are typically the better choice when cutting concrete.
Angle of cut
What is the best angle of the cut so that you don't disturb or break the concrete and yet still create the opening needed for conduit or another material? This is important to consider, but many homeowners often don't realize that drilling straight through concrete might not always be the best choice. For example, if your concrete has an aggregate or substance mixed in for texture and color, drilling straight down might break pieces of that aggregate and cause unsightly gaps in the concrete. Drilling at an angle might also allow for a more precise cut that isn't as likely to cause the concrete to split. A professional will understand these factors and ensure that the cut is done at the correct angle.
Stand or track
Concrete drill and saws usually have a stand or track that you attack to the floor or wall to ensure that you can control the tool and get a precise cut. These stands can be heavy and difficult to work with if you've never used one before, but a lightweight stand might not keep the drill in place as you need. A professional will know how to use a sturdy stand that won't be cumbersome or in the way but which will keep the operator and the cut safe.
Visibility and progress
When cutting or drilling concrete, visibility can be a challenge, but you need to ensure that you monitor your progress, as you often don't want to cut all the way through the material. A professional concrete cutter will know how to use LED lights on the drill to note the depth of the cut and may also need to adjust the size of the drill bit to cut only a certain distance and no more. If you're not familiar with how to use these accessories or pieces of the concrete drill in order to monitor the progress of your cut, it's best to leave the work to a pro.