Most people would have never even thought that Alexa and Cortana would ever join forces to make everyone's lives easier, but here we are.
According to CNET, users will be allowed to use either Cortona or Alexa on their devices such as a PC (which currently uses the former). These products have traditionally been separate and would have no option to ever work together, that's why a lot of people have the option to save money with this move.
This will enable two parties to get a lot of good features that were a previous weakness, now strengths. It's kind of like merging two things together to make sure both are strong. Both voice assistants might benefit from each other's advantages. Most notably, Cortona might benefit from Alexa's skills in smart home utilization, while Alexa might benefit from Cortona's deep knowledge of Microsoft products such as Outlook.
Users will need to actually enable the service in the feature settings of their device. This is good and bad. It can be great for those who would like to push their devices to maximum productivity, but for those who just want to use one device for simple things like turning the lights off and on, this could be confusing. Whatever the case may be, it's a good thing the user seems to have a choice in the matter.
For users on the Echo device, they should take the time to enable Cortona from the skills section of the app. You will need to log into a Microsoft account and that's something a lot of people really despise just because they don't use it often. In this case, it can be fairly useful, but it depends on your specific tasks.
Users need to also keep in mind that this feature is basically brand new. It does not mean it will be perfect and there will surely be some bugs because no one has ever really tried to do something like this. It even probably came as a surprise to those people who would have never thought both Microsoft and Amazon would work together on something like this. However, both companies tend to really care about the customer and the quality and usability of their devices to the max by a consumer. So, it makes sense that they would work together to ensure consumers have the option to be more productive than ever.
A device like this is likely to simply just forward a command to the device in question. Meaning, if someone wants lights dimmed, Alexa should do it and if someone wants to hear email and calendar updates, it is a good task for Cortona.