This is the 3951st most frequent Russian word.
единый
"Unified" or "single."
Here, 'единой' is used in the meaning of 'unified' or 'common', describing an attribute of the noun 'цель' (goal).
Мы должны стремиться к единой цели.
We must strive for a unified goal.
In this sentence, 'единая' is used as an adjective to describe the noun 'учебная программа' (educational curriculum), implying that it is the same or standardized.
Единая учебная программа необходима для всех школ.
A unified curriculum is necessary for all schools.
'Единого' in this context means 'consistent' or 'cohesive', referring to the noun 'подход' (approach).