Portable WiFi hotspot lets you share phone's internet connection (WiFi / Mobile data) with PC. Start mobile network sharing and activate hotspot on HTC One do as follows:
How to Enable WiFi Hotspot on HTC One?
1. Go to “Settings” app
2. Tap “More” under “Wireless & Network” category
3. Tap “Mobile network sharing”
4. Make sure “Portable Wi-Fi hotspot is marked
5. By tapping “Portable Wi-Fi hotspot settings” you can manage security, users and LAN