A container system comprising: a base unit comprising i) a base container portion having walls, including at least a first pair of opposing side walls (20a, 20b) and a second pair of opposing side walls (22a, 22b), the side walls defining an opening into an interior space in which articles to be transported can be stored, ii) a base handle having a first end portion attached to at least one of the opposing side walls (20a, 20b), a second end portion attached to at least another of the opposing side walls (20a, 20b), and an extending portion extending between the first end portion and the second end portion, iii) a first latch region and iv) a third latch region; and a removable container unit constructed and arranged to be removably attached to the base unit, the removable container unit preventing access to the opening of the base unit when the removable container unit is attached to the base unit and permitting access to the opening of the base unit when the removable container unit is removed from the base unit, the removable container unit comprising: a removable container portion having a storage space for storing items, a cover movable between an open condition permitting access to the storage space and a closed condition preventing access to the storage space; and a second latch region constructed and arranged to latch with the first latch region, a fourth latch region constructed and arranged to latch with the third latch region, wherein the container unit is attached to the base unit when the first latch region is latched with the second latch region and the third latch region is latched with the fourth latch region, and is removable from the base unit when the first latch region is unlatched with the second latch region by action separate from the pushing or pulling of the removable container unit to or from the base unit, and the third latch region is unlatched with the fourth latch region by action generated in response to or effected by pushing or pulling of the removable container unit to or from the base unit. a base unit comprising i) a base container portion having walls, including at least a first pair of opposing side walls (20a, 20b) and a second pair of opposing side walls (22a, 22b), the side walls defining an opening into an interior space in which articles to be transported can be stored, ii) a base handle having a first end portion attached to at least one of the opposing side walls (20a, 20b), a second end portion attached to at least another of the opposing side walls (20a, 20b), and an extending portion extending between the first end portion and the second end portion, iii) a first latch region and iv) a third latch region; and a removable container unit constructed and arranged to be removably attached to the base unit, the removable container unit preventing access to the opening of the base unit when the removable container unit is attached to the base unit and permitting access to the opening of the base unit when the removable container unit is removed from the base unit, the removable container unit comprising: a removable container portion having a storage space for storing items, a cover movable between an open condition permitting access to the storage space and a closed condition preventing access to the storage space; and a second latch region constructed and arranged to latch with the first latch region, a fourth latch region constructed and arranged to latch with the third latch region, wherein the container unit is attached to the base unit when the first latch region is latched with the second latch region and the third latch region is latched with the fourth latch region, and is removable from the base unit when the first latch region is unlatched with the second latch region by action separate from the pushing or pulling of the removable container unit to or from the base unit, and the third latch region is unlatched with the fourth latch region by action generated in response to or effected by pushing or pulling of the removable container unit to or from the base unit. a removable container portion having a storage space for storing items, a cover movable between an open condition permitting access to the storage space and a closed condition preventing access to the storage space; and a second latch region constructed and arranged to latch with the first latch region, a fourth latch region constructed and arranged to latch with the third latch region, wherein the container unit is attached to the base unit when the first latch region is latched with the second latch region and the third latch region is latched with the fourth latch region, and is removable from the base unit when the first latch region is unlatched with the second latch region by action separate from the pushing or pulling of the removable container unit to or from the base unit, and the third latch region is unlatched with the fourth latch region by action generated in response to or effected by pushing or pulling of the removable container unit to or from the base unit.