The capitalized readings are the On-yomi (Chinese reading) while the lower cased ones are the Kun-yomi(Japanese reading).
In charts like these, On-yomi are usually written in Katakana to indicate "foreign"-ness, while Kun-yomi are written in Hiragana.
Usually On-yomi are used in kanji combinations, and Kun-yomi are used in single kanji words / kanji+hiragana compounds like verbs or adjectives, etc.