First of all: Memory IC nomenclature is not robustly standardized; There is a lot of variation and even conflicting coding between manufacturers, on the order and meaning of the codes making up the part identifier.
That being said, here is an attempt at providing an overview:
The initial 2-digit code is the device family. A leading "24" indicates a I2C serially accessed EEPROM. Some other families are 95 (SPI serial EEPROM), Flash (e.g. 28F, 29F) and "standard" EEPROM (28).
Some manufacturers precede the 2 digits by a letter code, M for memory devices (STMicroelectronics, Atmel and others) optionally followed by an additional letter e.g. MX = Macronix memory.
Thus the device family becomes M24 for these examples.
The next letter or two usually indicates logic family / device voltage, but different manufacturers differ in their use of these codes:
- C = 5 Volts
- W = 2.7-3.6 Volts (sometimes 2.5 to 5.5 Volts)
- V = 3-3.6 Volts
- L = 4.5-5.5 Volts
- R = 1.8-5.5 Volts (typically STMicro)
- AA = 1.8-5.5 Volts (typically MicroChip)
- LC = 2.5-5.5 Volts
The digits after this do typically indicate memory capacity, but this is not simply the number of bits or bytes of memory. For instance, 512 = 512 Kilobits 8-bit EEPROM, but 516 = 512 Kilobits 16-bit EEPROM (usually, but not always!)
Some memory devices follow this up with a 2-digit access time code, i.e. access speed of the memory. Here again, 25 = 25 nanoseconds, but 10 = 100 nanoseconds usually.
This may be followed by a single or two-letter package indicator (B = Plastic DIP, N = TSOP, and a variety of other codes).
Last, a single-character (number or letter) device grade code may be added, i.e. various temperature ranges, military-grade, automobile grade, etc.
The only reliable way to interpret a particular memory IC's code, is to look it up in the datasheet, since there are wide variations, and even outright discrepancies, between manufacturers (and I suspect sometimes between production years too).
There are Application Notes for memory nomenclature by STM and several other manufacturers out there. Also, a fair guide to memory ICs, if somewhat incomplete, is here.
The first ROM devices had to have information placed in them via some mechanical, photolithographic, or other means (before integrated circuits, it was common to use a grid where diodes could be selectively installed or omitted). The first major improvement was a "fuse-PROM"--a chip containing a grid of fused diodes, and row-drive transistors that were sufficiently strong that selecting a row and forcing the state of the output one could blow the fuses on any diodes one didn't want. Although such chips were electrically writable, most of the devices in which they would be used did not have the powerful drive circuitry necessary to write to them. Instead, they would be written using a device called a "programmer", and then installed in the equipment that needed to be able to read them.
The next improvement was an implanted-charge memory device, which allowed charges to be electrically implanted but not removed. If such devices were packaged in UV-transparent packages (EPROM), they could be erased with about 5-30 minutes' exposure to ultraviolet light. This made it possible to reuse devices whose contents were found not to be of value (e.g. buggy or unfinished versions of software). Putting the same chips in an opaque package allowed them to be sold more inexpensively for end-user applications where it was unlikely anyone would want to erase and reuse them (OTPROM). A succeeding improvement made it possible to erase the devices electrically without the UV light (early EEPROM).
Early EEPROM devices could only be erased en masse, and programming required conditions very different from those associated with normal operation; consequently, as with PROM/EPROM devices, they were generally used in circuitry which could read but not write them. Later improvements to EEPROM made it possible to erase smaller regions, if not individual bytes, and also allowed them to be written by the same circuitry that used them. Nonetheless, the name did not change.
When a technology called "Flash ROM" came on the scene, it was pretty normal for EEPROM devices to allow individual bytes to be erased and rewritten within an application circuit. Flash ROM was in some sense a step back functionally since erasure could only take place in large chunks. Nonetheless, restricting erasure to large chunks made it possible to store information much more compactly than had been possible with EEPROM. Further, many flash devices have faster write cycles but slower erase cycles than would be typical of EEPROM devices (many EEPROM devices would take 1-10ms to write a byte, and 5-50ms to erase; flash devices would generally require less than 100us to write, but some required hundreds of milliseconds to erase).
I don't know that there's a clear dividing line between flash and EEPROM, since some devices that called themselves "flash" could be erased on a per-byte basis. Nonetheless, today's trend seems to be to use the term "EEPROM" for devices with per-byte erase capabilities and "flash" for devices which only support large-block erasure.
Best Answer
It seems clear to me. The FC component has a higher clock frequency, but it also has a lower maximum operating temperature. The LC extends this maximum operating temperature, but at the cost of some of the clock frequency.
That gives you the choice of either high temperature, or high clock frequency.