It's highly likely the most important part of technical analysis to trade because not only where you are in terms of time will affect the appearance of the chart, but what type of information you're receiving, what type of methods you can use, and the manner in which you're viewing patterns, price action, and indicators, so to be on a speed 1-minute or several behind a longer monthly, each one is showing another part of the story of the market, and some idea of how to view and approach each of them is a great trading edge. 

An interval is just a label for the time on which each bar or candle on a chart is labeled—for example, a 1-minute chart plots price action that occurred in each individual trading minute, a daily chart of price illustrates how the price acted over a full trading day, and a monthly chart of price plots an entire month's worth of price action summarized into a single candle. Markets use time frames to be able to look at trends, craft entrances and exits, and craft trades based on the level of aggressiveness or passiveness that they prefer to trade the market. 

The small time frames like the 1-minute, 5-minute, and 15-minute charts are usually used by scalpers and day traders who prefer fast intraday trading and make a large number of trades in one trading session, relying on making money from price movements within a minute. These charts are full of action, full of movement, full of potential at all times but filled with market noise—ghost movement creating spurious signals—and require instant decision, single attention, and strong control of emotions, so they are best left to the capable or naturally flexible trader. Further up, the 1-hour and 30-minute charts offer slightly slower pace and are generally intraday ones or for traders who like a couple of hours of holding time.

 Those time frames are day-tradable too, but cut out some noise and offer tighter entries than ultra-low time frames. And then there's the 4-hour chart, which is generally most popular among swing traders for the reason that it's somewhere in the middle on catching nice intraday moves and missing intraday craziness—it's a good gauge for short-to-medium term trends and allows for trades of any duration from a few hours up to a week or more, so it can be for those who don't want to spend an entire day glued to the screen. 

The day chart is also big time scale, which many of the part-time traders, the ones who have other things to attend to, like, you know, work or other responsibilities, because it gives you clean, high-quality signals, strong trends, and slower trading pace—you've got each candle represent a full trading day, so you've got your analysis once a day, get your trade in, and let the market do its magic without watching your screen. 

The larger are the weekly and monthly time frames utilized by position traders, long-term swing traders, and longer-term investors most interested in making big moves and letting trades run months, weeks, or years. These blocks of information give you information that tells you a "big picture" of the market and enable you to identify wide direction, large support and resistance levels, and long-term trend potential.

These may be useful in acclimating to your trade bias or cutting out negative setups. The single most impactful resource that any trader has is quite possibly multi-time-frame analysis, or analyzing two or three time frames at the same time hoping to pick up the big picture of the market—big picture trend direction on outside time frame all the way to exact entry points on the inside. 

For example, the swing trader would look at the day chart in order to get a glimpse at the big picture of the trend, then bottom down to the 4-hour chart to look at a pullback entry, and then have a very brief look at the 1-hour chart before taking a position. This keeps you with your focus on the bigger picture of the market without being held hostage by minute-by-minute time frames, and it improves timing and reduces risk. But comprehend that every time frame operates at its own pace, and to put all of them together into too great a mix or switch from one to another back and forth is to have confusion and ambiguity. 

Traders run into issues when they have opposing signals on disparate time frames—e.g., a buy signal on the 5-minute but a downtrend on the day chart—and can't determine which time frame is dominating in their system. To avoid this, it’s helpful to choose a “base” time frame that matches your trading style and personality—for example, if you’re a swing trader, your base might be the daily chart—and then use other time frames for support. 

And various indicators react differently on different time frames—e.g., a crossover by a moving average on a 1-minute chart will create a short-term scalp, while the same crossover on a week chart will create a month-long trend. And then, while you're trading using technical indicators like RSI, MACD, or Bollinger Bands, keep in mind that their signals are in relation to the time frame on which and in which you're trading and trading in an unsuitable time frame for your needs can mislead you with false signals or entice you into trades that go against your plan. 

The main point is that types of Timeframes in Trading are similar to lenses—you are viewing the same market, just using varying levels of zoom, and the most effective traders learn how to decipher those perspectives clearly, merge them intelligently, and select the one that works best for their trading personality and objectives. Whether you enjoy dirty scalping or patient, thoughtful swing trading, mastering how to read each timeframe and what that's telling you in terms of the marketplace is most rewarding about technical analysis and what all traders should understand so they can begin to make money consistently.