Imagine a hypothetical example: a transiting planet is at 15 degrees Libra. In one chart, Venus sits at that degree—so the two are conjunct. In another, Saturn is at 15 degrees Capricorn, about 90 degrees away; that angle is called a square. The sky at a given moment is the same, but the comparisons with the two charts are different.
An astrologer also looks at which house a planet is moving through and what other relationships the chosen school takes into account. Aspects also involve an orb—the permitted distance from an exact angle—and different schools may set it differently. This kind of reading requires birth details, especially the time if houses are involved. “I’m a Libra” is not enough to reconstruct the whole chart.
Planetary positions and the angles between points can be calculated. A transit by itself does not tell you the date of a meeting, argument, or promotion: the interpretation of an aspect depends on the chosen school and the context of the natal chart.
The stars speak. The choice is yours.