If you read about Chinese tea for long, you will meet the word gongfu, and it can sound like a skill you must master before you are allowed to enjoy tea. It is not. Gongfu brewing and mug brewing are simply two ways of handling the same leaves, and most tea drinkers use both, at different times of day.
What gongfu brewing actually is
Gongfu brewing uses a small pot or a gaiwan, more leaves than you would use in a mug, and many short infusions. You might steep the same leaves five, eight, or ten times, pouring each infusion out into small cups. Because each steep is short, the flavour changes gradually: the first cup may be light and fresh, a later cup richer or sweeter, and the last cups softer again.
This way of brewing is good for paying attention. It asks for ten or twenty minutes, a small table, and not much else going on. It is also a good way to get to know a tea, because you taste it changing instead of tasting only one version of it.
What mug brewing actually is
Mug brewing is what most people do at work or at home without thinking about it: leaves in a mug or a strainer, hot water, a few minutes, and one steady cup. You can top the mug up, or re-steep the leaves once or twice if you like, but the point is ease, not precision.
This way of brewing is good for real life. It works while you are reading, working, or talking, and it does not require a special pot or a free half hour. A good tea should still taste good in a mug. If a tea only tastes good under perfect conditions, it is not a very forgiving tea.
How to choose between them
In gongfu vs mug brewing, choose by time and mood, not by rules. If you have a quiet evening and want to slow down, use the small pot. If you are busy, cold, or just want a warm cup, use the mug. The same oolong can be lovely both ways; it will simply show different sides of itself.
A practical tip: use slightly more leaf and shorter steeps for gongfu brewing, and less leaf and a longer steep for a mug. In both cases, pour the tea out rather than leaving the leaves sitting in the water, or the cup will keep getting stronger and more bitter while you drink it. The Tea Brewing Timer has both modes built in — pick gongfu or mug and it adjusts the time for you.
Do you need special equipment?
No, not to start. A mug with a strainer is enough for mug brewing. For gongfu brewing, a small teapot or a gaiwan helps, but it does not need to be expensive or traditional. Many people begin with one small pot and a few cups, and add nothing else for a long time.
The real difference in gongfu vs mug brewing is not the equipment. It is the pace. Gongfu brewing slows you down on purpose. Mug brewing fits tea into a day that is already moving. Both are Chinese tea culture, and both count.