You share in a covalent bond, and if they're shared perfectly equally, it's a 100% covalent bond. If they're not, it's partially ionic.
Basically, when comparing covalent with ionic bonds, you have a spectrum:
- 100% ionic - no sharing of electrons at all.
- Mostly ionic, partially covalent - some sharing of electrons, primarily skewed towards one atom.
- Mostly covalent, partially ionic - significant sharing of electrons, only slightly skewed towards one atom.
- 100% covalent - exactly even sharing of electrons.
So yeah, 100% covalent bonds, or ideal covalent bonds, have equally-shared electrons.