Trend reversal - simple approach

What is trend reversal? I define it as the existing or current trend direction has changed. 

Example. 

Price is moving UP directional and this motion no longer in motion. Instead the price direction has switched or changed from UP to either Down or Sideway.

What is defined as DOWN in this case? There are different school using different parameters to define this. Some might define as price breaking last 5 days low or others might define it as price breaking a certain % of the total move or another might say price need to break last 3 recent lows. Another group might say if price break a certain moving average parameters on either daily or weekly or monthly chart. Maybe another trend line practitioners might apply the trend line technique.

I prefer to use the term trend change instead of reversal simply because trend do not only move UP and DOWN, it also move SIDEWAY. This sideway exists and we cannot simply expect a trend that is UP will automatically change to DOWN but it can actually go sideway instead of down.

On the reverse, a DOWN trend need not necessarily change to UP but it can also go SIDEWAY.

When SIDEWAY phase ends than the greater force will decide if the emerging new trend will be UP or DOWN.

Once we debunk the wrong concepts and lay a proper foundation than it will be easier to move forward correctly