'concrete' originates from Latin, specifically the word 'concretus,' where 'con-' meant 'together' and 'crescere' meant 'to grow.' 'Focus' originates from Latin, specifically the word 'focus,' meaning 'hearth' or 'fireplace,' which evolved to mean 'center of activity or interest.'

'concretus' transformed into the Old French word 'concret,' and eventually became the modern English word 'concrete.' 'Focus' retained its form from Latin to modern English.

Initially, 'concrete' meant 'grown together' or 'solid,' and 'focus' meant 'hearth.' Over time, 'concrete' evolved to mean 'tangible' or 'specific,' and 'focus' evolved to mean 'center of interest.'