Choosing a web hosting plan that can accommodate high traffic on your website largely depends on the specific needs and requirements of your website. If you're expecting around 2 million visitors per day, then it's essential to consider a plan that can handle such a large amount of traffic without compromising your website's speed and performance.
In terms of the difference between professional and enterprise plans, it typically boils down to the level of support and resources offered by the hosting provider. Professional plans usually have resource limitations and fewer features compared to enterprise plans. They are ideal for moderately-sized websites or those with lower traffic volumes.
On the other hand, an enterprise plan is designed for websites that require a high level of performance, speed, and customization. This type of plan typically offers dedicated resources, advanced security options, and priority support to ensure your website stays up and running smoothly.
Overall, if your website receives 2 million visitors per day, it's generally recommended that you opt for an enterprise plan to ensure the best possible performance and reliability. However, I would suggest doing more research and considering different hosting providers to find the one that best suits your website's specific needs and requirements.