"Ängström" is a word that represents 1/10,000,000,000,000th of a centimeter. That's pretty small. Why do we care? Leo says it's because it's the new measure of the latest processors, known as 20A processors. So when you upgrade your PC, you're going to be hearing that term. The more transistors you can get on a processor, the more powerful they become. Up until recently, processors had been plateaued due to Moore's Law (which stated that transistors would double every 18 months). That had caused chip makers to put multiple processors on a chip. But we're at the end of Moore's Law now.
Intel has run up against a wall in Moore's Law that said that the number of transistors in a processor would double every 18 months. In the last few years, Intel has been up against a wall, not being able to double the speed. But a recent breakthrough has created a transistor using a single atom! That will enable processors to become faster and smaller, using very little energy.