With the exception of the Hiragana and Katakana audio modes, there are three main flashcard modes for the decks at JPDrills: Normal, Kanji to English, and Kanji Readings. Normal mode provides all information available: kanji, reading, and English.The Kanji to English mode strips away the kanji reading and the Kanji Reading mode strips away the English.
For speaking and conversation, the Normal flashcard mode is arguably sufficient. The other two main modes are for users who wish to also become literate and proficient at kanji. The Kanji to English mode exists for much of the same reason as the famous Heisig method, to gain an intuitive sense of the meaning of the kanji itself before attaching the Japanese way of reading it. After users have completed the Kanji to English mode of a flashcard deck, they often move on to the last step: learning the Japanese reading of the kanji they just gained an intuitive sense for. They do this with the last flashcard mode: Kanji Readings.