What is a digital business card?

It does the job a paper card has always done, which is to leave someone with your name and a way to reach you. The difference is where the details live. A paper card carries them in ink. A digital business card carries them on a page that belongs to you, and what you hand over is the address of that page.

Because the details live on a page, they can hold more than a card could print: a photo, links to your work, your social profiles, a booking link, a short line about what you do. And because the page is yours, you can change it. A new phone number or job title goes in once and everyone who has your card sees the new version the next time they open it.

Under the surface it is three ordinary pieces of the web. The first is a page at a fixed address. With Umbel that address is umbel.me followed by your handle, so a card might live at umbel.me/@mary. The second is a vCard, a small file in a format every phone has understood for decades, which is what lets the person you meet press one button and have you appear in their contacts with the right fields filled in. The third is a way of getting the address onto their phone without anyone typing it, which is where QR codes and NFC come in.

None of this needs an app on either side. The page opens in whatever browser the phone already has, and the contact is saved by the phone's own contacts app. That matters more than it sounds: people are willing to point a camera at a code, and they are not willing to install something for a stranger.

• QR code: you show a code on your screen or a pass, they point their camera at it, and the card opens.
• NFC tap: a small chip in a card or tag is written with your card's address, and holding a phone near it opens the card.
• Link: you paste the address into a message, an email signature or a profile bio.
• Wallet pass: the card sits in Apple Wallet or Google Wallet, with its QR code ready, so you can share it from the lock screen.

Most people end up using two of these. The code is for meeting in person; the link is for everything else.

Paper is handed over once and then fixed. The card you gave someone in March still says March's phone number in October, and once the box is printed, a typo stays. A digital card is never fixed: it is read live each time, so it says what is true today.

The other difference is what comes back. A paper card tells you nothing after it leaves your hand. A digital card can show you how often it was viewed and which links were pressed, and it can carry a short form so the person who received it can leave their details in return. Umbel calls this share-back, and it turns a one-way exchange into a two-way one.

A digital card needs the other person's phone to have a connection to open, and some people still prefer to be handed something they can hold. The card can also feel less personal if it is treated as a web page rather than a card, which is why the design matters. A plain, well-made card that looks like a card, not a form, does better in a room than one that looks like a website.

There is also the question of where it lives. A card hosted by a service depends on that service staying up. It is worth choosing one that lets you export your details, and keeping a plain vCard of yourself somewhere safe.

Anyone who meets people and wants to be remembered: founders, sales teams, estate agents, consultants, tradespeople, photographers, recruiters. Teams tend to arrive when someone notices that every reprint costs money and every leaver's cards go in the bin. A digital card is reassigned, not reprinted.