For example, I can completely define that holding a stock for 1 year is short-term and holding it for more than1year is long-term.

General understanding:

Ultra-short-term generally refers to buying and selling on the same day, such as warrants, foreign exchange and futures. This trading system is T+0, allowing entry and exit on the same day, while the Shanghai and Shenzhen A-share markets are T+ 1, which means buying on the same day and selling after the next day.

Short-term: generally, it will be operated within one week and half a month, which is probably the time interval.

Midline: half a month to several months or even 1 year.

Long-term: 1 year or more, typically Buffett.

In addition, some technical indicators can be used in both short and long term, as long as you change the time type of K-line chart to 60-minute chart, weekly chart or monthly chart.