verb: allocate; 3rd person present: allocates; past tense: allocated; past participle: allocated; gerund or present participle: allocating
distribute (resources or duties) for a particular purpose.
Example: "The authorities allocated 50,000 places to refugees."
How to allocate more RAM for Minecraft Servers:
Usually, servers work fine with the stock amount, assuming you don't have too many players.
Usages of more memory:
More RAM for multiplayer map buffering (less reloading)
Better working with RAM intensive mods
More view distance
Faster first world generation
Less lag with more players
Faster map rebuild
What is RAM?
RAM stands for Random Access Memory. It is the memory space that applications use to work in, like the desk space you have in your office cubicle or something. Most laptops have 2-8GB of it, and average gaming rigs have anywhere from 8-24 (on average, anyway. Some can have up to 32 or 64). The amount of RAM an application has determines how fast it can possibly work.
This tutorial requires that you've installed a full Java version, (Java SE) on your system. Else it might not work right. Installing the right Java version (also important: 32/64 bit) often solves many problems.