Trading's generally focused on shorter-term gains (though people do trade long-term positions and swing trade as well), and investing's generally focused on longer-term gains. A lot of traders, especially recently, also trade on leverage and thus use precise plans to limit losses as much as possible while letting winning trades run and earn profit, whereas investors can have greater tolerance for shorter term fluctuations in price, because they aren't as big of a deal for those people over a longer timeframe.
What you need to know to profitably sell and buy? How are such plans built? What information are they based on?
you need experience, and most importantly familiarity with the market.
for example to make profit from altcoins you need to be able to be able to notice when the pumps are beginning and also be able to notice when they are coming to an end so that you could get out before others dump.
there are a lot of small things too. for example what is hype and FUD, and which hype and FUD are effective and which ones are just desperate attempts.
all these could help you make better decisions about your entry and exit points so you end up with much better results. and hopefully you learn from the mistakes you make to end up with a better final result in long term.