The term 'Oxford' refers to any style of footwear with a 'closed' lacing system, where the facings are stitched flush with the rest of the shoe. The word 'brogue' refers to the punched detailing, which at one point was used to let water out of country shoes; these days, they are purely decorative.
Semi brogues are an excellent halfway-house between formal toecaps and decorative brogues. They can be dressed up or down, offering a similar level of versatility to other brogues