Under Regulation (EU) No 910/2014 (eIDAS), a Simple Electronic Signature (SES) can be as basic as a typed name. An Advanced Electronic Signature (AES) has to meet four specific requirements under Article 26 — uniquely linked to the signer, capable of identifying them, created under their sole control, and tamper-evident. A Qualified Electronic Signature (QES) is an AES created on a Qualified Signature Creation Device, backed by a qualified certificate from a provider on an EU member state's Trusted List.
Only a QES carries the direct legal-equivalence guarantee across every EU member state. SES and AES are both legally admissible, but with lighter evidentiary weight — the right tier depends on what's actually being signed, not a default setting.