A mobile hotspot (tethering) is a phone feature that shares the phone’s mobile data connection with other devices over Wi-Fi, Bluetooth or a USB cable. Your phone acts as a small router, so a laptop, tablet or a companion’s phone can get online through your data plan.
For travellers this turns one eSIM into connectivity for a whole bag of devices. Most travel eSIM plans permit tethering, though a few restrict it, so confirm before relying on it for work. Speed for the connected devices matches whatever the phone itself receives, and enabling it is a single toggle: Personal Hotspot on iPhone, Hotspot and tethering on Android.
Three realities deserve attention. Laptops consume data very differently from phones: cloud sync, system updates and video calls can empty a travel data allowance in hours, so pause backups and updates before tethering. Battery drain is heavy, since the phone runs its radios hard in both directions; keep a power bank handy. And plans with a fair usage policy may slow speeds after heavy consumption, a threshold that sustained tethering reaches much faster than normal phone use.
The usual comparison is with pocket Wi-Fi, the rentable dedicated router popular in parts of Asia. A hotspot does the same job with no extra device to carry, charge or return; the trade-offs are covered in eSIM vs pocket Wi-Fi. Families weighing one shared plan against several individual ones should read the family data sharing guide, because sharing keeps everyone tied to whoever holds the hotspot phone.
A concrete example: on a train through the Alps, one traveller enables a hotspot and a partner’s laptop joins the network to catch up on email. One eSIM, one prepaid bill, several devices online. If your connection needs to survive serious remote work, the remote work internet guide explains how much data headroom to plan for and when a backup connection is worth having.