"Samskara" can be translated very nearly by inherent tendency.
Using the simile of a lake for the mind, every ripple, every wave that
rises in the mind, when it subsides, does not die out entirely, but
leaves a mark and a future possibility of that wave coming out again.
This mark, with the possibility of the wave reappearing, is what is
called Samskara. Every work that we do, every movement of the
body, every thought that we think, leaves such an impression on the
mind-stuff, and even when such impressions are not obvious on the
surface they are sufficiently strong to work beneath the surface,
subconsciously.
What we are every moment is determined by the sum-total
of these impressions on the mind. What I am just at this moment is the
effect of the sum-total of all the impressions of my past life. This is
really what is meant by character; each man's character is determined by
the sum-total of these impressions. If good impressions prevail, the
character becomes good; if bad, it becomes bad. If a man continuously
hears bad words, thinks bad thoughts, does bad actions, his mind will be
full of bad impressions; and they will influence his thought and work
without his being conscious of the fact. In fact, these bad impressions
are always working, and their resultant must be evil; and that man will
be a bad man; he cannot help it; the sum-total of these impressions in
him will create the strong motive power for doing bad actions; he will
be like a machine in the hands of his impressions, and they will force
him to do evil. Similarly, if a man thinks good thoughts and does good
works, the sum-total of these impressions will be good; and they, in a
similar manner, will force him to do good even in spite of himself.
When
a man has done so much good work and thought so many good thoughts that
there is an irresistible tendency in him to do good, in spite of
himself and even if he wishes to do evil, his mind, as the sum-total of
his tendencies,will not allow him to do so; the tendencies will turn him back; he is
completely under the influence of the good tendencies. When such is the
case, a man's good character is said to be established.
Source: Teachings of Great Masters