Offensively, Ground is one of the most powerful types. It is the only type super effective against Electric, and is super effective against five types in total, a coverage matched only by Fighting, which is also super effective against the Rock and Steel types. The other types are Fire, Rock, Poison, and Steel. Even though Grass- and Bug-type Pokémon resist Ground attacks, many of them lose this resistance due to secondary typings with a weakness to Ground (such as the common Grass/Poison and Bug/Poison types).
Ground-type physical moves are commonly known and have many potent options, most notably Earthquake, which has high attack power and widespread compatibility due to its TM status in every generation. Single-target physical moves such as Bonemerang and High Horsepower can be generally considered inferior options to Earthquake; however, unlike Earthquake, their damage is not reduced by the effect of Grassy Terrain, and they are far less risky to use in Double and Triple Battles. Ground-type special moves pale in comparison, considering the relatively low Special Attack stats of the majority of Ground-type Pokémon. The special Ground-type move with the best mix of utility and power is unquestionably Earth Power.
Ground's greatest disadvantage is its ineffectiveness against common Flying-type Pokémon and those with Levitate (unless they are grounded). However, most Ground-type Pokémon can learn Rock-type (mainly those available via TM such as Rock Slide) moves to take down Flying-types, Bug-types (which resists Ground), and also Ice-types (which Ground is weak against).
Generation I introduced the most Ground-type Pokémon of any Generation, with 14, and Generation VI introduced the fewest, with two.
Generation I introduced the most Ground-type moves of any Generation, with six, and Generations IV and V introduced the fewest, with two each.
Generation VI is the only Generation to not introduce a pure Ground-type Pokémon.
In the anime, Ground-type Pokémon's immunity to Electric-type attacks is treated inconsistently, sometimes upheld and sometimes ignored. The anime (in particular Showdown at Pewter City) also implies that Ground's immunity to Electric has a limit depending on the voltage, as Brock's Onix, when first fighting Pikachu, was completely unaffected by Pikachu's electricity, but in the rematch, Pikachu's electric attacks, having been boosted at an abandoned hydroelectric plant, were giving Onix a noticeable degree of pain, although it still was not enough to completely incapacitate it, as well as environmental factors (such as water being sprayed on it).
Each type that resists Flying is weak to Ground, and vice versa.
More Pokémon are immune to Ground-type moves than any other type, as both Flying Pokémon and levitating Pokémon are immune to Ground.