'Far' is an adjective used to describe something at or to a great distance. It can be used to refer to either physical or metaphorical distance.
1. It's a far journey to that mountain.
2. He is a man of far vision.
When using 'far' as an adjective, it often comes before nouns to describe something that is more distant in comparison to another thing. 'Far' as an adjective often carries a sense of remoteness or being further away from a reference point. Don't confuse the adverbial use of 'far' (e.g., 'How far did you go?') with its adjectival use (e.g., 'the far end').
as an adverb, 'far' describes the extent, distance, or degree of something. It can refer to physical distance or to a metaphorical extent.
The village is far from the city.
I didn't realize we had walked so far.
How far have you gotten in the book?
'Far' can be combined with 'too,' 'so,' 'as,' and 'very' to modify its degree (e.g., 'too far,' 'so far,' 'as far as,' 'very far'). 'Far' can be used both in literal contexts (referring to actual distances) and figurative ones (referring to extent or degree). Be cautious with the comparative and superlative forms. While 'farther' and 'farthest' traditionally refer to physical distance and 'further' and 'furthest' can refer to both physical distance and degree or extent, in modern usage, they are often used interchangeably.