What are decimal places in cryptocurrency?

Could you elaborate on the concept of decimal places in the realm of cryptocurrency? I'm curious to understand how they function and their significance in this digital asset class. Specifically, what role do they play in determining the value of coins and tokens? Are they standardized across all cryptocurrencies, or do they vary depending on the specific coin? Furthermore, how do decimal places affect the transactional aspects of cryptocurrencies, such as fees and speed of transactions? Lastly, is there a limit to how many decimal places a cryptocurrency can have?