'improvement' originates from Middle English, specifically the word 'emprowement,' where 'em-' meant 'in' and 'prow' meant 'profit.' 'Focus' originates from Latin, specifically the word 'focus,' meaning 'hearth' or 'fireplace.'

'improvement' changed from the Middle English word 'emprowement' and eventually became the modern English word 'improvement.' 'Focus' has remained largely unchanged from its Latin origins.

Initially, 'improvement' meant 'profit or advantage,' but over time it evolved into its current meaning of 'making something better.' 'Focus' has retained its original meaning of 'central point of attention.'