Even when you know exactly what you want, there's still room for artistic interpretation. And, if you only have a general idea, multiple concepts let you explore different design directions and choose your favorite.
For example, here's 3 Waves Capital; Our client wanted to see a couple text-based logos (wordmarks), and a couple traditional designs with a wave icon that could be used on its own.
Our normal turnaround is 4 business days, but if you need it faster you can pay extra to jump the queue and we'll present you with your concepts within 1 or 2 work days.
These graphics are an extension of your brand, and are typically constructed out of elements related to your logo. Here are a few examples for social media.
This is the tiny icon that appears in browsers near your site's name.