These two terms are often used interchangeably, however, they DO have their differences. Quality Control refers to ensuring the quality of the products or the deliverables. This includes the search for defects on the deliverables through peer reviews and testing. And this is primarily what [company name] testers are expected to do. Quality Assurance, on the other hand, looks more into the process of preparing the deliverables.
For instance, in your projects, you would notice that there are guidelines, standards, defined procedures and metrics for tasks done by developers and testers. These are examples of QA mechanisms as they try to ensure that the development of the product is kept on track and that the requirements of the system/client are met. Similarly, QC tries to help ensure that requirements of the system/client are met. But this is achieved through reviews and testing which expose the inadequacies and defects of the product.
One simple way to put it is that QA is process-oriented while QC is product-oriented.