'essential' originates from Latin, specifically the word 'essentialis,' where 'essentia' meant 'being' or 'essence.' 'focus' originates from Latin, specifically the word 'focus,' meaning 'hearth' or 'fireplace.'

'essential' changed from the Latin word 'essentialis' and eventually became the modern English word 'essential.' 'focus' transformed from the Latin word 'focus' and became the modern English word 'focus.'

Initially, 'essential' meant 'pertaining to essence,' but over time it evolved into its current meaning of 'absolutely necessary.' 'Focus' initially meant 'hearth' or 'fireplace,' but evolved to mean 'center of activity or interest.'