A trading algorithm is a systematic set of trading instructions written in computer language that informs a machine of what to do with a piece of information. It takes about 600,000 microseconds for a human expert to make a decision within his field of expertise. With algorithms, these kinds of decisions can be executed in 100 microseconds.
It may not be surprising to learn, therefore, that the majority of our financial system has been entrusted to them. Today, three quarters of trading decisions are made by machines, not humans. Their speed of data assessment and decision making gives them an advantage over any human mind.
With an expert advisor you can trade without being influenced by greed or fear or even simple ordering mistakes. What trading level you have is not relevant. Complex algorithms and money management tools are all implemented in EA software. They scan the markets day and night in multiple currency pairs to find interesting trades for you.
Expert advisers can make rapid calculations and forward extreme fast ordering. However, an algorithm has hardly any clue about the trend. A trend means that a market will go into one direction for a longer time period. Money management is key and you should always keep an eye on the market while your EA is doing all the trading for you.