A connector comprising: a housing configured to be mounted on an upper surface of a printed circuit board, PCB, and including a sidewall having an empty space that is open to one side, and a fixing portion extending from an outer surface of the sidewall, the fixing portion being configured to pass through the PCB; a connection terminal having a part passing through the sidewall of the housing and an other part being configured to pass through the PCB and configured to be electrically connected to the PCB; and a connection unit including a terminal receiving portion having a part inserted into the empty space of the housing and a remaining part extending out of the housing through the open side of the sidewall and a plurality of connection holes into which a connection terminal of another connector is to be inserted, and a coupling portion extending from an outer surface of the terminal receiving portion toward a position of the fixing portion to be mechanically coupled with a part of the fixing portion extending out of the PCB, wherein the fixing portion has a fixing protrusion that is coupled to the coupling portion, the fixing protrusion extends downward from a bottom of the sidewall of the housing and linearly extends in a horizontal direction, wherein the coupling portion includes: a pillar extending out downward from a bottom of the terminal receiving portion; and a hook extending from a lower end of the pillar toward a position of the fixing protrusion, and an end of the hook in an extending direction is configured to be coupled to the fixing protrusion. a housing configured to be mounted on an upper surface of a printed circuit board, PCB, and including a sidewall having an empty space that is open to one side, and a fixing portion extending from an outer surface of the sidewall, the fixing portion being configured to pass through the PCB; a connection terminal having a part passing through the sidewall of the housing and an other part being configured to pass through the PCB and configured to be electrically connected to the PCB; and a connection unit including a terminal receiving portion having a part inserted into the empty space of the housing and a remaining part extending out of the housing through the open side of the sidewall and a plurality of connection holes into which a connection terminal of another connector is to be inserted, and a coupling portion extending from an outer surface of the terminal receiving portion toward a position of the fixing portion to be mechanically coupled with a part of the fixing portion extending out of the PCB, wherein the fixing portion has a fixing protrusion that is coupled to the coupling portion, the fixing protrusion extends downward from a bottom of the sidewall of the housing and linearly extends in a horizontal direction, wherein the coupling portion includes: a pillar extending out downward from a bottom of the terminal receiving portion; and a hook extending from a lower end of the pillar toward a position of the fixing protrusion, and an end of the hook in an extending direction is configured to be coupled to the fixing protrusion. a pillar extending out downward from a bottom of the terminal receiving portion; and a hook extending from a lower end of the pillar toward a position of the fixing protrusion, and an end of the hook in an extending direction is configured to be coupled to the fixing protrusion.