1. Card
A card or fob with a chip (RFID, MIFARE, HID). Cheap, fast, easy to issue and block. The downside: a card can be lost or lent.
2. Fingerprint
Biometric identification. A fingerprint is not lent and not lost. The downside: pricier readers, and every employee's prints must be enrolled.
3. NFC and phone
NFC runs at 13.56 MHz and lets the phone be the key. Contactless and modern, but it needs compatible readers and phones.
4. Combination
For most sites a combination works best: a card for daily passage, a fingerprint for high-control zones. One platform manages them all.
5. What happens when a card is lost
The card is blocked in software in seconds. The person gets a new one; the lost one stops working. That is the advantage over a key — no lock change.
6. Rights by time
Rights are defined by person, door and time. A worker enters only on working days, a cleaner only in their shift. The system enforces the rules you define.
7. Recommendation
Start from what you protect. For an entrance, a card is enough. For a store or server room, a fingerprint. For a modern space, NFC in the phone.
RULE OF THUMB: Identification follows the value of the zone. A plain door gets a card, a high-security zone a fingerprint.