The Reconnaissance Battle

Whenever two enemy forces draw near each other and combat is in the offing, both sides should be trying to find out all they can about the enemy. The information obtained by reconnaissance can provide protection for ones own troops, while possibly identifying vulnerabilities of the enemy.

Most enemy vulnerabilities are found behind the lines. In war, it is stupid to attack an enemy strongpoint, it is better to strike an enemy weak point. The reconnaissance battle looks for gaps, or weak points, in the enemy dispositions.

Secondarily, battlefield reconnaissance can identify avenues of approach, bottlenecks, key terrain, water points, cover and concealed areas, and open or danger zones. Battlefield reconnaissance can spot enemy mine fields, forward observers, ambushes, counter reconnaissance screens and/or roadblocks.
A commander that does not send out scouts as far ahead of nis main body as possible is asking for defeat.

From Fast-Moving; Hard-Striking War:
“The main objective of the first (Finnish Army’s) Motti phase (reconnaissance and stopping) was to stop the enemy column on its approach road. Harassing patrols struck the enemy column from all directions while its advance was impeded by temporary roadblocks and delaying actions. At the same time a reconnaissance battle was fought to eliminate enemy reconnaissance assets and determine, "...the enemy's strength and groupments, route of advance, mobility...strength, quality of armament and equipment and communications and supply routes. ... The Finns conducted terrain evaluation and marked routes for their own motti operations..." This phase was marked by guerrilla methods of ambushing, raiding, mining and other hit-and-run tactics designed to create fear and desperation in the enemy ranks.”