You determination that keys and scales are not the same is correct. They are not the same but in general - most scales are based on a particular key. Let me try to explain keys and scales in simple terms without getting into a great deal of music theory.
Keys determine the group of notes that the composer has to choose from when composing the music. In Western Music there are twelve notes that exist between octaves. They are A (A#/Bb) B C (C#/Db) D (D#/Eb) E F (F#/Gb) G (G#/Ab). The letters in the parenthesis are the same note in practical application because they are played by the same key on piano or same string/fret combination on guitar and in the same place on all instruments that have a fixed tuning system. So there are keys on the piano which would play a note which would be referred to as either an A sharp (A#) or B flat (Bb) - depending on which key you are in.
Of the twelve notes, only seven exist in each key. A key can be major or minor. The key signature tells which notes on the musical staff are to be considered (and played) sharp or flat. The key of C major has no sharps or flats thus the key signature shows no sharps or flats. The seven notes in the key of C major are C D E F G A and B.
A scale is an ascending series of notes (each one higher than the preceding note) that span an octave. Scales are typically based on a key. So the C major scale would consist of the the notes C D E F G A and B. So to play a C major scale on an instrument, you would start on C and play C D E F G A and B and end the scale by playing C one octave higher.
The following types of scales contain 7 notes each: Major, Natural Minor, Harmonic Minor, and Melodic Minor. The pattern of intervals between notes (either whole or half step/semitone) is what determines the type scale. These seven note scales are called diatonic scales.
In a major diatonic (7 note) scale the pattern of intervals is whole whole half whole whole whole half. Whole is two semitones and half is one.
So there is one full (whole) step between the first two notes of a diatonic major scale and one full step between the 2nd and 3rd notes but only a half step between the 3rd and 4th notes. In a natural minor scale the intervals are whole half whole whole half whole whole.
Scales can also consist of 5 notes. 5 note scales are known as pentatonic scales and also span an octave. But to span an octave with only 5 notes, larger steps or gaps between notes are required. Just as with diatonic scales, there are different types of pentatonic scales (ie major and minor) and again the pattern of intervals between notes is determined by the type scale (or you could say the pattern is what determines the scale type).
Other variations of scales can be invented by the musician to add a particular flavor to their music.
In summary, scales are played in ascending note order and are usually based on a particular key (with the exception of the chromatic scale which is all twelve possible notes played in ascending order). The key determines which notes are available to choose from for a particular scale. In general, scales will contain notes derived from the key it is based on. So a major diatonic scale will contain the same notes as the key it is derived from. C major scale shown above contains all the notes in the key of C major - played in ascending order.
A major pentatonic scale would also use notes from within the key it is derived from - but only 5 of the seven notes would be used.
Think of a scale as climbing or scaling a ladder. The key and type of scale determines how far apart the steps on the ladder are from one another. Pentatonic, or diatonic determined how many steps on the ladder. Each ladder is the same height (an octave) but the spacing for a 5 step ladder is going to be different that for a 7 step ladder.
Hope that helps.