Fundamental analysis is a framework that aims to identify the "true" value of an asset. Fundamental analysts study economic and financial factors to figure out if the  market's valuation of an asset is fair. Those factors could be macroeconomic factors like the state of the global economy, the overall industry condition, or businesses connected to the asset (if there are any). 

Again, the goal here is to establish whether an asset is undervalued or overvalued. Suppose that Alice rigorously studies a cryptocurrency – Bobcoin – which trades for $10. But Alice's findings indicate that the asset should actually be worth $20. In this case, she might decide to buy lots of Bobcoins as she believes that the market will eventually value them at $20. 

On the topic of cryptocurrency-specific fundamental analysis, it's worth noting that some consider on-chain metrics when conducting their research. On-chain metrics are an emerging field of data science. It is  concerned with data that can be read from public blockchains: network hash rate, distribution of funds, the number of active addresses, etc. By taking this abundance of public information, analysts can create sophisticated indicators that measure the network's health. 

Fundamental analysis is popular in the stock markets, but it's perhaps not very suitable for cryptocurrencies in their current state. The asset class is so new that there simply isn't a standardized, comprehensive framework for determining market valuations.  

What's more, much of the market is driven by speculation and narratives. 

As such, fundamental factors will typically have negligible effects on the price of a cryptocurrency. However, more accurate ways to think about crypto asset valuation may be developed as the market matures.