Moving averages are important technical indicators that every investor should know. A breakdown of a stock price below these levels is seen as a weakish trend for a stock or the index as the case maybe.
DMA is also called daily moving averages. So, a 50 DMA means the average closing price of a stock for the last 50 days. On the other hand a 100 DMA means the daily average price for the last 100 days.
Both these are important indicators when determining the movement of a stock. Technical analysts use this very frequently.
Fundamental analysts on the other hand care very little for the moving averages. Their stocks picks are more based on the fundamental analysis of a stock more than anything else.
They might tend to ignore technical analysis altogether.