A magazine's monthly horoscope is written once for an entire zodiac sign — for millions of different people at once. A personal yearly forecast works differently: it's built not from a sign, but from your own natal chart — the exact planetary positions from the moment you were born, which haven't changed since.
It works through transits — the real, present-day movement of the planets across the sky, mapped onto the fixed points of your chart. When transiting Jupiter crosses your natal Sun, that's one aspect and one window of opportunity. When transiting Saturn forms a tense aspect to your natal Venus, that's a completely different window, with a different character. Over a year, a lot of these passages add up, and a forecast is a breakdown of which ones land in your particular year and what each one means.
The finished reading is laid out month by month: some months the energy works in your favor (favorable), some call for more care (challenging), some are mixed, and some are quiet periods with no notable transits. It's not a list of predictions of "what will happen" — it's a map of energetic windows: what's worth starting, and what's better postponed, when you have a choice.
That's the difference from a magazine horoscope: two people with the same zodiac sign will have transits landing on completely different points of their charts — because their houses and exact planetary positions differ — so their years unfold differently. The forecast is based on the real positions of the planets, the same data as the natal chart, cross-checked against independent sources, not on generic lines that fit everyone at once.
Build your chart and get your yearly forecast for free — the forecast is calculated from an already-built natal chart, so that's the first step.