Stick welding (formally Manual Metal Arc Welding, MMAW, sometimes SMAW for Shielded Metal Arc Welding) uses a flux-coated electrode held in a stinger. The arc burns the electrode down as it welds, and the flux melts and provides its own gas shield over the weld pool.
Stick is the toughest, most portable welding process in the trade. No gas bottle. Works in wind. Welds through paint, rust, and surface contamination that would defeat MIG. The trade-off is that it's slower than MIG, leaves slag that needs chipping off, and requires more operator skill to lay a clean bead.
Stick is the on-site choice for gate post repairs, rural and remote welding, and any thicker-section job where MIG would struggle for penetration. A 6010, 7016, or 7018 electrode covers nearly every steel-gate situation.