what exactly is biasing in transistors and how to do biasing
It's not clear what you read, but the conditions for forward active operation of an npn transistor are

$$V_{be} &gt; V_f$$

$$V_{ce} \ge V_{ce}(\mathrm{sat})$$

\$V_f\$ is typically around 0.6 or 0.7 V and  \$V_{ce}(\mathrm{sat})\$ is typically around 0.2 V.

Some texts will say that \$ V_{ce} &gt; V_{be}\$ is required for forward active operation, and this is a reasonable rule to ensure that a reasonable output signal can be achieved without distortion. But the transition from forward-active to saturation is fuzzy, so either rule could be used, depending on what behavior is under discussion.

That is, the base-emitter junction must be strongly forward biased, and the collector must be biased at least slightly above the emitter.

But there is no junction between the collector and emitter regions, so it doesn't particularly make sense to talk about whether they're "forward" or "reverse" biased relative to each other.