1. Within means not outside a place.

Pattern: be + within + noun
Those schools are within the county jurisdiction.
There is too much commotion within the building.

Typical nouns used after within:
area, building, city, country, county, jurisdiction, state, territory, walls

2. Within means less than a period of time.
I will return within the hour.
He will finish within five minutes.

3. Within means less than a distance.
There is a hospital within five miles of the school.
The storm was within ten miles of our town.
4. Within means possible; not exceeding the limits of something.

Pattern: be + within + (one’s) noun
At last, the beach is within sight!
A fortune is within our reach if we are lucky.

Typical nouns after within:
bounds, hearing, range, sight, reach, the law, the limit, the rules

5. Expression

to keep within the family—to not reveal something to anyone who is not a family member
That man has a strange history, but they keep it within the family.

Fact
Most cell phone antennas have no purpose other than to make people believe that flipping up a 2 inch antenna just gave them better reception. They are not connected to any circuitry.      .. More >>