The idea in one breath: An uptrend is a sequence of higher highs and higher lows. That is the whole definition, and it is worth having a mechanical one because "it looks like it is going up" is how traders end up buying the fourth leg of a move that ended two weeks ago.
What counts as a swing point
A swing high needs at least three bars either side making lower highs. Loosen that and you get a swing point every few candles, at which point the concept stops filtering anything and every wiggle looks like structure.
Reading the sequence
Mark the swings, then read them in order. Higher high, higher low, higher high — that is an uptrend and pullbacks are worth buying. The moment you get a lower low, the sequence has broken and you are in something else until proven otherwise.
The useful discipline is doing this before forming an opinion. Structure read after you already want to be long is not a reading, it is a justification.
Mark the most recent higher low — the level that has to hold for this uptrend to still be an uptrend.
Break of Structure
A break of structure is a close beyond the most recent swing point in the direction of the trend. A wick through that level is price being rejected from it — which is the opposite signal, and mistaking one for the other roughly doubles your signal count while ruining all of them.
Continue the track