Distinguish between alkali and base

The key difference between alkali and base is that the group 1 elements are categorized as alkali elements whereas any element or compound having basic properties are categorized as a base.

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.

i do not get it   at all